SSD Optimization

I thought I would try to cover SSD issues and optimizations that have been discussed in one place, also I would be interesting in looking up further questions if anyone has one.

SSD alignment:

You not only get much more speed (Good for those with an SLC), but you also get less wear, which is especially important for those folks with an MLC drive. Essentially, if you own any SSD it needs to be aligned manually. There are rare cases where an SSD does not need to be aligned, such as a single partition drive without a partition table and without a boot sector, but those situations are VERY rare.

The process is fairly simple, but you end up using command line tools. The process can help any system, including XP, Linux, Mac. Apparently Windows 7 and Windows Vista automatically create and align the data blocks for an SSD, I have not personally verified it, but it is written as such in the Microsoft literature.

The process using linux to prep the drive for any system:
1. Make backups of all data on all drives connected to the "subject" computer.
2. Erase the disk and clear the partition table. (fdisk on Linux can setup both Windows and Linux partitions)
3. Load a modified fdisk that forces the drive to use 1024 byte cylinders.

4. Create a partition starting from the second cylinder
5. If you wish to have additional partitions simply make the initial partition less than full size and create additional partitions.

Now your disk partition is aligned, now we need to populate that partition with a usable filesystem that will be usable for your application. (NTFS, HFS, EXT4, etc.) It is important that you do not allow your OS installer to format its own partition, otherwise your work will be wasted!

To create an aligned partition using Linux:
You need to mkfs whatever (NTFS, HFS, EXT4) that you need for your choice of operating system. If you created additional partitions you need to run this for each.

Example using the Linux ext4 filesystem:

If you have time for testing you can vary the stripe width, stride, and block size, to try to find an optimal point for your particular SSD, but these settings worked very well for me.

Now that our ext4 partition is aligned with our drive partition, and our drive partition is aligned with our SSD we are ready to install.

With Ubuntu you would run a normal install, until you reach the disk setup portion:
1. Select manual partitioning
2. Select each partition in turn and change their folder assignments
3. Verify that the format box is NOT checked in any of your partitions, as the partition should already be empty and reformatting would break the alignment
4. Continue the installation

For Windows:
1. Hopefully you will have already created a NTFS partition (FAT32 for pre XP systems) above with the proper alignment.
2. Begin installation
3. Select use existing disk without formatting, as the partition should already be empty and reformatting would break the alignment
4. Install

Voila! You have a full speed SSD, and it will likely last longer that the poor drives that did not get an alignment.

One of the better posts on the HOWTO of SSD alignment. The above instructions are modified from this source.
Aligning an SSD on Linux

SLC vs MLC:

SLC
Pros
Speed, and very long life. Usable in server and enterprise applications.

SLC
Cons
Cost, small storage space, and limited shopping options due to the decrease of SLC production to make room for more MLC production.

Also not all SLC drives are created equal, the Intel M25-E are rated for 100,000 writes to each cell, whereas a lesser SLC off brand may only be rated for 10,000 writes to each cell. If you want the best, buy the high end enterprise units. Intel, Kingston (They use Intel chips) and Samsung are some of the best SLC units that I am aware of. With the best drives usable for 10+ years operating life in a 24/7 enterprise environment.

MLC
Pros
Inexpensive, relatively large amount of storage space.

MLC
Cons
Short lifespan, lower speeds. NOT usable in an enterprise or critical environment. More susceptible to data loss from EMP and electrical surges.

Again not all MLC drives are equal. Some newer MLC drives use a "Dual Channel" or "Multi channel" architecture to greatly improve usable speeds. Again as with SLC some use inferior chips and have a rated life of only 500-1000 writes per cell, whereas the best MLC chips can have a life of almost 10,000 writes per cell.

With wear leveling it can take quite a bit of time to write to each cell 10,000 times so these drives could theoretically be usable for quite some time. But they also must read and write in blocks, so you are actually writing more than you might think. On some drives if you change one bit, it might have to erase and rewrite an entire block (Common erase block sizes are 128kb to 512kb) to change that one bit!

That means that one bit change just cost you the equivalent of 128,000 512,000 of your precious few writes to your drive each time you write even a tiny file, and that could be double that if your partitions are not aligned. (As it might have to erase and write two blocks instead of one.) Now with 512,000 bytes erased per write, that is the equivalent of "burning out" 51 bytes @ 10,000 writes per bit, for each and every write. (10,000 writes per bit is the best any current MLC can theoretically do)

On a truly massive MLC drive such as a large 250GB drive, losing the equivalent of 51 bytes of data per write may not seem significant, and it really is not even noticeable with the automatic wear leveling, but it IS happening. An equivalent SLC drive will be "burning out" 5 bytes of data storage per write.

Your hypothetical 250GB MLC drive has approximately 4901960784 individual write operations before it will be "out" of write cycles. (Almost 5 billion write operations) However it is very likely to fail well before this point, especially if your drive is near full capacity, and it has limited unused space to wear level with. For instance if your 250GB drive was 90% full with movies that you are never going to delete, any "wear leveling" will occur in the remaining 25GB of space. This multiplies the write operations in this area and will result in that area wearing out in 1/10th the time, or about 500 million writes. Now the rest of your drive is just fine, but that area of the drive will fail and thus cause the entire drive to be rendered worthless.

http://www.google.com/url?sa=t&sour...saz2CA&usg=AFQjCNH9_mT_2QLkFRCBxDF9AdJ_UESe-w

SSD's write in 4kb segments but must erase in 512kb blocks not as stated

The main problem with MLC drives is that they are far more electrically sensitive, as their cells have four states instead of the two states of the SLC drives. (That is how they hold more data for the same price) Imagine a light bulb that could be ON , Partially on, Partially off, or OFF. In the case of an outside electrical or electromagnetic interference, it does not take that much "energy" to make one of these bits distort slightly in one direction or another, and alter that bit enough to create a read error.

In the case of a larger surge it could functionally erase the entire drive! A standard mechanical HD is in this case would have much more reliability than a MLC drive. In addition a drive that was affected may not be recoverable by standard forensic techniques if the data has been significantly distorted.

Both the short lifespan (Shorter than regular HD's in an enterprise setting) and the electrical sensitivity make these drives unusable for mission critical applications. Personally I would buy a standard HD before I "went out on a limb" with a relatively expensive MLC drive, that may or may not outlive a standard mechanical hard drive.

SSD's in general:

Some of the older "first generation" SLC and MLC drives were also not SATA or PATA compliant. They have problems including short lifespans, high power usage (in some cases higher that standard mechanical hard drives), and low throughput. Beware if you have an older SSD that gets hot, it may not be reliable for long term critical data purposes.

As far as upgrading older computers, the mechanical hard drive has been the choke point for a long time. With processors and networks capable of moving an incredible amount of data, our old mechanical hard disk has never had the capability to catch up and preform as well as the rest of the system. This was somewhat mitigated with raid arrays but they are still inferior. Your dual 10k drives in a raid 0 may be able to beat the throughput of a SSD, but it's slower access time is a significant hindrance. A good SLC SSD can read and access many different files at once, and access them much faster.

SLC SSD's can bring new life to an old computer. That ancient Thinkpad or Toughbook can outpreform a modern system with a SSD upgrade, it makes the old computers of yesterday usable and modern. I notice when my unaligned (soon to be rectified) Toughbook boots in twenty seconds (including POST) and my friends newer Turion X2 64bit takes more than a minute!

Philosophical SSD:

A $700 intel X25-E may be expensive, but if you could transfer that to your next five laptops would it be worth it? And if it securely held your data for the rest of your life? How much is that kind of reliability and security worth? I guess it depends on your application, as it may be "cheap" for a business to keep its bookkeeping or vital records on such a drive. (Preferably with regular backups) It could also be cost effective if your time is valuable, think about if your computer is ready a few seconds earlier, and processes take a few seconds less. Those seconds add up, and if a $700 drive gets me back a few hours or more of my lifespan, is that worth it?

Saving 30 seconds (Booting a toughbook with a SSD instead of a mechanical hard drive once a day) a day for the ~12,000 days that I have left would add four days to my usable lifespan, or about $168 a day. If I use the computer a lot and it saves five minutes a day (My current Toughbook with SSD probably saves me more than that), then I will gain almost 41 days of my life back, maybe not a lot in the grand scheme of things, but I'll take an extra month of usable life for $700. Of course I will probably use the extra usable time of my lifespan tinkering with Toughbooks, so your mileage may vary. The more you use SSD enabled computers, the bigger your time savings will be.

I think the fundamental questions need to be asked, a SSD can alter many things in your life, (especially your bank balance ) and if something as simple as a hard drive upgrade can help, then why not? If you spend a lot of time on the computer, or you have "better" things to do with your time, a large one time expense can deliver gold. It is a lot like in the old days, when a RAM upgrade brought a slow memory starved behemoth up to "normal" speeds, only in this case you are taking a "storage throughput" starved computer and giving it significantly faster disk access.

My old Mk3 Toughbooks only hold PATA drives, so the SSD selection is very restricted. I am hoping to acquire a newer Toughbook that can take a very nice enterprise SATA SSD like the Intel. If my old 1.4ghz toughbook can outperform almost any computer I have used, what could a newer SATA toughbook do?

Final conclusion, buy a very nice SLC SSD for each computer that you use on a regular basis, and align it properly. Each will likely outlive you, and during that time they will provide you with more usable time to live, learn, and tinker with Toughbooks.

It boggles the mind.



References:
SLC vs MLC: Especially MLC voltage leakage and lack of enterprise usefulness.
http://www.supertalent.com/datasheets/SLC_vs_MLC%20whitepaper.pdf

SLC 50,000 writes, MLC "A few hundred writes for four bit cells", 1000 - 5000 writes for three bit cells.

http://www.seagate.com/docs/pdf/ssd_faq.pdf

Erase blocks
managedflash.com/news/papers/easyco-flashperformance-art.pdf

Why MLC is inferior
http://www.ramsan.com/podandvid/slc_vs_mlc.htm

 

Respectfully, there are alot of points that should be clarified in the post. Much of it is a result of very outdated information and there are alot of things that just are not correct such as your beginning with a discussion on alignment. There is no need to even consider ssd alignment when doing a basic installation of Vista or Windows 7 as it sets everything up fine. You should amend and put that at the beginning so as not to alarm a new user.

Also, when discussing the difference of mlc/slc, I dont know of any slc which have ever advertised as little as 500-1000 writes per cell and, in fact, I can't find anything that even advertises 10000 as you discuss and I have been on the ssd bandwagon since day one. The standard fr the slc is 100000 writes. I couldnt imagine any mlc or slc only affording 500 writes per cell which would result in an extremely short life span.

As well, ssds write in 4kb segments but must erase in 512kb blocks not as stated, "On some drives if you change one bit, it might have to erase and rewrite an entire 4k block to change that one bit"

Another statement,"Personally I would buy a standard HD before I "went out on a limb" with a relatively expensive MLC drive, that may or may not outlive a standard mechanical hard drive."... In todays ssd arena there is not a single ssd that will not outlive a harddrive and well, yu should do a bit of background before dissuading anyone to purchase a ssd. The benefits of an ssd put it in a class of its own and extend far beyond the fact that any ssd will probably outlast the system that it is installed in. There are plenty of articles which speak to all the benefits.

Again this is totally incorrect: "Both the short lifespan (Shorter than regular HD's in an enterprise setting) and the electrical sensitivity make these drives unusable for mission critical applications." SSDs have been relied upon for years...well longer than retail release, for many typical mission critical environments where the ssd could not survive. These include fighter jets for there incredible speeds and turns, environmental applications in the extreme north and south as well as many medical and other aeronautical applications where the hard drive simply cannot be trusted. The ssd has been around a bit longer than you might expect.

Finally, you speak about the ssd saving you boot time but it so much more than simply that. Many simply clone their drives when changing to the ssd which results in a similar boot than the original...a great deal longer than it has to be. The trick is to do a clean install and educate oneself on the specifics of proper ssd optimization so they know the things that might assist them such as whether AHCI is enabled, write buffering is on, system restore, pagefile and on and on.. Educate the new ssd enthusiast and there is no better protection down the road.

I apologize if this reply isn't quite what you were looking for but there are alot of things within that just aren't factually correct, the first starting with the blanket advise to align. I might suggest a bit more background on ssds before you jump in just to make sure we get the right word out there. I am no expert and don't believe that that word is cognizant of anyone in the ssd arena just yet but, having reviewed so many ssds (many or which were the first to be reviewed on the net, slc and mlc, here at NBR)... I just believe we need to put the correct word out there.

If I could refer you to some nice articles...Anand has done some great stuff and the Anthology is a good start.

 

Thank you for your reply, it has given me a good chance to look over what I wrote, and hopefully fix some of the more glaring errors. I was not aware that Vista and Windows 7 compensated for the alignment, and hopefully the boot sector allocation. (I am not sure how they do it, but they say they do, and I own some MSFT so I hope it works out for them)

The 500-1000 was for MLC drives, not SLC. And if you look at Seagate's article written in March 2010, their estimate for SLC drives is 50,000 writes and depending on the technology MLC can be anywhere from "hundreds" to 5000 writes. And yes, MLC drives do have a very short lifespan if you are constantly using them, that is why the big enterprise shops use SLC ONLY! There is not a professional level application (as far as I know) in existence that is running on MLC drives.

A standard hard drive will run for many years at full workload, a MLC drive at full workload is good for only 1.2 years on average based on these guys and their testing:

http://www.ramsan.com/podandvid/slc_vs_mlc.htm

You also have the additional problems with a large variance in quality of both the SSD controllers, and their actual storage chips. Remember the old days when you could get two identical spec'd RAM chips from different brands? Usually the nice (and more expensive) brand name was faster and likely more reliable. It is the same with the controllers and NAND chips on SSD's, you could get a nice Intel, Samsung, or other high end brand. They are probably closer to the SLC rating of 100,000 cycles, since the weed out a lot of the "lesser" chips in the manufacturing and testing process. (Where did those old Intel Celerons came from? They were "defective" Pentium chips) And guess where those "lesser" chips go? They go right into the "inexpensive" and no name bargain brands!

A 16GB SLC SSD from brand X, will ABSOLUTELY have different characteristics and lifespan than a visually identical 16GB SLC SSD from brand Y, and that one will ABSOLUTELY have different characteristics and lifespan than a visually identical 16GB SLC SSD from the same brand Y. I think the old saying "you get what you pay for" counts with SSD's as well, as a cheap SSD is probably missing some feature or lifespan that the more expensive ones have.

Hopefully I am not dissuading anyone from buying a SSD, I would just hope that they understand that their MLC drive may technically be a SSD, it lacks the main benefits of the technology while still incurring a much higher cost, I would not consider MLC drives to be a mature technology at this point.

I would have recommended MLC for long term storage if it did not suffer the electrical sensitivity effect, but with that problem it renders MLC drives truly unsuitable for ANY critical application. Again MLC drives are "Consumer grade" not "Useful long term and high reliability grade".

If you want a "real" SSD, you MUST buy a SLC drive, and hopefully a quality drive that shows all of the beauty and speed of a real SSD. In fact if you can afford it, go out and buy one now, but a nice quality SLC SSD and stick them in your Desktop, Laptop, etc. It is cost effective for most users and is so "worth it".

The MLC drives are in my opinion just for "show", and should not be purchased by anyone at anytime for any reason.

Corrected to include the common erase block sizes of 128kb to 512kb.

Referring to MLC drives, not SLC drives.

Again those are ALL SLC SSD's, and they are a proven and mature technology. The MLC drives that manufacturers are "pushing" on the public are a sad shadow of what real SSD's are capable of.

You are correct, there are a lot of "tricks" to optimize SSD's, but I have found that alignment is one of the best performance gains possible. You can explore to your hearts content all of the OS specific tweaks and tricks, but I did not cover those here. You are more than welcome to link to good ones, as I am interested in improving speeds as well!

Thank you for time, please let me know if there are any other glaring omissions or obvious errors. I currently own about 12 SSD's including one 60GB OCZ MLC drive, (Which works fine for now) and one Intel X-25E (Fast even when my initial alignment was off!)

I think you made a false assumption on your website regarding SSD life, the MTBF number is not intended for single units, it is intended for large installations to give them a rough estimate on how many spares they will need to maintain their operations. It also fails to account for write life, which is especially important for MLC drives.

I have had two 1 million MTBF SSD's fail on me and I only ran them for maybe 100 hours each. Quality control issue? Probably. But in any case any one specific drive has nothing to do with MTBF numbers. The best MLC drive out there run at full throughput will likely fail in an average of 1.2 years. That is barely over 10,000 hours (10,512), hardly the 2-4 million MTBF numbers being thrown around by the manufacturers.

Please post them here, if they help us all out than I am a happy goose!

 

Ok...

I was going to point out a number of things but can probably finish off my contents with a general note and some suggestions.

First off, I am going to hazard to guess since your system was a PATA system and you speak of drives up to only 16Gb that you are not really that experience in the typical ssd manner which might include mlc ssds.

The basic facts of mlc ssds is that we are seeing less and less slc ssds for sale because of the amazing jumps that has been made with mlc that go further than the simple performance results and price. You are now seeing mlc ssds such as the OWC RE mls drive which are capable of doing the job that only slc drives could do in the past.

I might agree a bit more with you if you recommended slc for business and non-consumer purposes with mlc for the consumer because the true fact is the slc cannot get anywhere the consumers pricepoint to make an effective alternative to the hard drive.

I am also aware tha you are perusing Seagate articles, a company without any ssds as of yet and speak of the reliability of the hard drive in comparison to the ssd. If you examine the Google study which was done on hundreds of thousands of hard drive service results, you will see that the typical hard drive actually has a very poor lifespan in reality and there was a study done on the site some time back which had alot of response where we saw typical brands of drives not even lasting 3-5 years by many responders.

The mlc ssd, however, through logical calculation can return a life much greater than 10 years and through a calculation of thoroughput of 5-10Gb writes per day logically can last 5-7 times that without question.

Yes I am aware of my MTBF postings back in 07 but something we should all realize even today is that the industry is blindsiding us with MTBF calculations. The typical ssd box still says LIFE EXPECTANCY: 1.5 million hours or over a hundred years...

This is just wrong...

We can say something without question that is a fair comparison and that is that the typical ssd will outlast the average computer where there are not many that would trust the same as their hard drive.

Your further view with respect to the ssd lasting only 1-2 years is extremely unrealistic by any means and I can attest to that personally having tested, used and retained countless ssds over the years which retain their original performance results even today. I firmly believe that if I cant kill an SSD, something needs to be said for that.

In todays market, I dont think you can find an ssd that would dare advertise anything less than a write thoroughput of 10000 much less a preposterous estimate of 500 or 1000 writes. That simply would not sell.

Further, with respect to ssds, in todays market, most are the exact same drive simply separated by a companies firmware and thats it as can be seen by the new SandForce drives.

Finally, I might suggest you choose your reading material much more carefully because alot of it is just incorrect and I hate to see it believed by those new to the industry. The average consumer will never see slc at an adequate price and that is simply because of the price of single cell NAND.

We are watching ssds slowly push aside hard drives and pretty much the only thing left for the hard drive is its capacity which, again is only a matter f time. I know Seagate is working on a full fledge mlc and WD has already released one. HD manufacturers will all have to do this or soon lose the business they have relied upon for so long to survive.

 

Actually I currently own 4 PATA SLC SSDs that are 16GB and I own more than 8 SATA SLC SSDs that are all 32GB and above. I also own one MLC SSD that operates just fine at the moment, though not with any critical data, and after a required firmware update from OCZ.

No matter what updates they make to the controllers or the chips, the MLC drive technology is fundamentally flawed, all the way down to the core of the storage chip. They were built that way because it is much cheaper, not because it is better. If price and storage capacity were no object would any MLC drives exist at all? Probably not, as anyone who understands how fragile they are and how tenuous they hold data would never actually use one. I own one, but that was a test case, now that I know how worthless they are I will save my pennies for a good SLC drive.

I think the "basic fact" is that manufacturers want to cheat the consumer as much as possible. Why else would they be selling large MLC drives for high prices when they KNOW that those MLC drives do not share the wonderful attributes that the SLC drives have. MLC drives have a much higher profit margin, and so far they have not yet been "found out" as to how terrible they actually are. This will happen eventually, and already a large segment of the population has experienced problems with MLC SSD drives, just check out the review boards at any major online retailer, or the review boards at OCZ or any other large MLC dealer. The truth is out there.

When I see a white paper that shows an MLC drive running for more than a year in a heavy enterprise environment, then I might change my mind. Until then they should be avoided at all costs for any use that data loss might result in monetary losses. I currently consider purchasing an MLC drive to be a monetary loss, so take it for what it is worth.

Feel free to link to any fact sheets that prove me wrong on MLC drives.

Google's study was a perfect example of why you should completely ignore MTBF and "Life Expectancy" jargon from the manufacturer. If they have been lying for years about how long their mechanical drive will last, do you actually think they are going to tell the truth about their SSD lines? Unless they suddenly became "honest" overnight after releasing their SSD drives. Anyone believing a manufacturers lifespan numbers needs to have their head examined.

Price points are another silly marketing thing, those $700 SLC SSD drives are actually cost effective for the average consumer, they just don't know that. Those inexpensive MLC drives with large storage capacities are the marketeers saying "Hey look you can have one of those really nice 250GB SSD drives for 1/8th the cost" But they are selling you something completely different, the old bait and switch.

And folks like you without a clear understanding of the differences between MLC and SLC are perpetuating the myth that MLC drives are "consumer grade" or "just as usable" as the SLC drives. This is a false assumption, and if you are going to compare them on their merits, you should also compare them on their faults.

I listed the pros and cons (as I understand them) above, if you have any issues with those facts please let me know and I will research and update them.

And Seagate does produce SSD drives:
Pulsar Solid State Drives | Seagate
200 GB of SLC beauty @ only 1.3 watts of operating power! Just don't ask how much it costs!

I will believe it when I see it. Or if you give me a link to a reputable source that explains the really long lifespan of an MLC SSD. Their common failure modes are not accounted for in a standard MTBF calculation, so no current MLC drive made can or will EVER last for 1 million hours of running time, I can guarantee that for a fact. If in 114 years you still have a working MLC drive that has 1 million hours on it's counter, then I will owe you a beer!

That is just marketspeak for "our drives will last a really long time. And they are based on the same MTBF numbers. If a large corporation had 1.5 million installed SSD drives. They could reasonably expect one to fail per hour of use. This does not help the consumer at all, and those numbers are also heavily inflated.

A human has a MTBF of 800 years, how many 800 year olds do you see running around?

Read this more more information. Not SSD related, but it explains MTBF numbers in a very easy to understand manner:
http://www.enecsys.com/downloads/UnderstandingMTBF.pdf

I would argue that in heavy use cases, or high electrical surge situations would render a MLC drive less useful than an identical mechanical hard drive. You may see it a different way, but the enterprise folks currently share my view.

That is not just my view, check with any major enterprise SSD manufacturer, they will tell you the same 1-2 years in an enterprise environment.

And how many of those countless SSD drives were MLC drives? You are operating on the false assumption that MLC drives have the same wonderful attributes of your tried and tested SLC drives.

I realize that you were "suckered" by the MLC craze as well, with your signature proudly including an "OWC Mercury Extreme Pro 120Gb SSD", it probably works fine now, but at some point in time it will die and my little 16GB SLC SSD will still be trucking along (Since it technically has the lifespan write capacity the equivalent of a 160-320GB MLC drive). Tell me, did you need any firmware updates, or have you noticed any slowing yet? It will eventually happen to you and you too will feel cheated.

I now understand why you have so vehemently defended MLC drives, and I am not immune to such ignorance, I bought one of the cursed things as well (A 60GB OCZ for $300 bucks no less), and by golly don't I feel like a "shaved tail". I could have had almost paid for a useful for a very long life 32GB SLC Intel X25-E. Imagine 640GB MLC write endurance equivalent and without the electrical sensitivity, and with much higher speeds, and the ability to actually use all of the space without "Killing" the drive significantly earlier, for the same price! Now can you see why MLC drives are such a bad investment?

Hopefully it works out better for you then their 50GB model that was their last "Cool Upgrade" drive as read below. Note the very large section at the top detailing that the "New" drives don't have the same massive flaws and failures of the old drive controllers. I would hope so! Of course their controller fixes cannot solve the underlying MLC design faults.

OWC Mercury Extreme 50GB:

http://www.anandtech.com/show/2948

They PLANNED for their MLC drive to suffer from 20 gigabytes of bad blocks, and they accounted for this in their design. Any guesses as to why they need to allocate so much extra space to bad sectors? Because MLC drives eat their sectors alive!

Another helpful link:
On professional-level 28% over-provisioned SandForce SSDs, these NAND modules may combine for 128GB of physical storage space yet only 100GB of this capacity is designated for data. Consumer-level SandForce SSDs receive 7% over-provisioning and 128GB devices will yield 120GB of usable storage space.
http://benchmarkreviews.com/index.php?option=com_content&task=view&id=536&Itemid=99999999&limit=1&limitstart=3

The MLC chips in your drive are rated for 3000-5000 writes.
http://benchmarkreviews.com/index.php?option=com_content&task=view&id=536&Itemid=99999999&limit=1&limitstart=3

Again the devourer cometh! Your drive only has 7% over provisioning, are you somewhat aware of what you actually bought? Your drive will only last for 1.2 billion writes, and that is assuming you get the full 5000 writes out of all 128GB of ram chips, that also assumes your disk alignment is proper and you don't write files larger than 512kb, and that is also assuming that your disk is completely empty. If your drive is currently at 50% capacity your available writes goes down to 600 million writes. While a comparable SLC drive would still have 12 billion writes left at 50% of disk capacity.

If you take it to the next logical step, someone with their drive at 90% of capacity will only have 120,000,000 write operations available, make sure to keep your MLC drive squeaky clean to keep it alive. A full MLC drive will die very quickly! At 99% capacity (A full drive) you are using up the available writes on only 1% of the drive, leaving you with only 12,000,000 writes. Your drives over provisioning can help alleviate this to an extent, but the numbers are sound, and your drive is doomed. You went from 1.2 billion writes to 12 million writes, simply because you had the audacity to use the space you paid for! An empty MLC drive will last a long time, but one of the big reasons people buy MLC drives is because they can hold more "stuff". Does that sound counter intuitive? I think so.

That may sound like a lot of writes left, and it is. But it is actually a lot less "useful time" than you might think. As each cell is burned out and replaced with one of your 8GB in over provisioning, (And that will probably extend your drives useful life for a while, of course it is space that you paid for and can't actually use.) it will amplify the amount of writes to the remaining sectors, thus the more you write to it, the faster it will fail. Installing windows 7 Home Premium for instance uses a MINIMUM of 28000 write operations. (Based on the average install size of 14GB and assuming a perfectly effective use of storage space with 14GB of 512kb files each using exactly one sector)

Assuming everything was perfect and your drive was empty you could install Windows 7 to your drive over 48,000 times, sounds like a lot right? Of course remember that is assuming that it uses its space PERFECTLY, it does not actually have to write more than once per sector, and you don't actually write anything to the drive between installs. An SLC can write ten times as much (20 times in this case), is it worth it to pay half the price for twice as much storage space, and 1/20th of the lifespan? Don't forget that these drives are very sensitive to transient voltage and EMI, that alone could possibly damage your data (Think X-ray machine at the airport or electrical surge) even if it does not actually use up your precious write cycles.

If they came out with a 2TB MLC drive, it may put of the "day of death" from writes, but it will still suffer from a weakness to EMI, even then will it be worth it?

Anyone know how many write operations Windows makes per second when it is running? I am sure that it is not low. Heaven forbid you have an swap file or use a 24/7 P2P program on a MLC drive!

There is a reason that MLC drives are taboo in professional data centers, they simply can't take the constant writes. Some brands have tried to market their MLC drives as "Enterprise grade" or "Prosumer" but I have yet to see one installed in any actual enterprise system.

Mechanical hard drives are a proven technology, and SLC SSD drives are also proven, but these mysterious MLC drives that call themselves SSD drives have yet to be proven, spend your money if you want to, but as for me and those I know the big sign says "RUN AWAY!"

These are less than HALF the 10,000 write rating you are touting for the best MLC drives out there. You are absolutely right in that they would probably not sell. That is why marketeers have to do a little thing called stretching the truth. They tell you that their wear leveling will make up for the MLC drives inherent flaws, they are wrong, and it is the consumer that will ultimately pay the price with the loss of their "valuable" data.

Not sure what you mean there. Are you talking about MLC drives that are all starting to use the same controller? There are many competing controller sets and some are getting to be very good. But no matter what controller you use, there is still the root problem of the base NAND chips that cannot be compensated for by the controller in MLC drives.

Please don't post a blanket statement that my article is incorrect. For the sake of myself and others tell me where I am wrong and point me to articles and white papers that will correct me. I welcome the challenge!

I would suggest that we both do a little more research, I know that there are flaws in what I wrote, but there are also obvious flaws on your website and in your posts. And I have done you the honor of pointing some of your flaws out. Feel free to link to any reputable articles to prove me wrong, but as far as I can see you are operating on quite a few false assumptions as well. Again please don't post your opinions without some evidence to back them up, and please point out the same if I do so. I would be happy to look it up and correct myself.

So long as what we both seek is the truth, and we are willing to learn from our mistakes, then once this article is done we should have a very accurate portrait of the SSD world. And you can help make it happen by helping me correct my flawed data with valid references and white papers.

You are correct, SSD drives will eventually completely control the market, and after our current love affair with MLC drives is over, and they are seen for the waste of capital that they are, we can finally start working with "pure" SLC drives. And hopefully the dark memories of those dreaded MLC drives will not taint the market for the good SLC drives.

 

I dont quite to know how to answer you except that you need to examine the industry right now to understand that:

1. SLC ssds cannot come down to the consumer price point simply because SLC NAND is very expensive.

2. The consumer does not want to pay an enormous amount as you have for a SLC drive without a sufficent capacity for storage.

3. Only with MLC NAND which is much cheaper than SLC NAND can a manufacturer make an SSD which is within the consumers price range.

4. The consumer is demanding performance, capacity and value which can be done with mlc drives whereas it cannot with SLC.

5. MLC drives have already proven themselves and they are responsible for the untouchable sales increase within the past 3 years and not SLC drives. SLC drives are only a drop in the bucket for overall sales.

6.. It seems that only you, of all websites and reputed experts,believe that the mlc drive is worthless and will only last a year and a half or so.

I don't know where to go from here because your vast amount of completely false statements puts us at a real impasse. There has never been, to my knowledge, any ssd that has reported its write thorough put at 500 writes per cell. I don't know where anyone could even imagine such a thing.

Anyone with a knowledge of the industry and the ssd build process knows that most ssds are exact clones manufactured and sold to manufacturers. This started from day one when Samsung sold ssds to Crucial who pulled the sticker off and changed the firmware. This has occurred with just about every manufacturer except those who manufacture their own controller as well such as Memoright. Do you know how many manufacturers are selling the Intel X-25m under their own name? Do you think there is any difference in the hardware within?

With respect to some new SandForce drives, have you seen two competing manufacturers drives side by side and open? They are identical.

As far as manufacturers stretching the truth, I am going to have to ask you to give me one simple example with fact behind it. Its almost as though you believe there to be a industry wide conspiracy to defraud the consumer.

Anyway.... we can go back and forth forever but I have to say that most of what you say is way out there...way out there. Its like you are there trying to convince everyone who will read this that the world is flat.

In closing, I will read any response you may provide but cannot respond further. An effective debate or exchange first has to start with both parties providing somewhat of a believable and logical viewpoint.

 

The easiest way to align a SSD for Windows XP is to use my Win 7 RC disk to install Win 7 RC, delete the 100mb partition that Win 7 places at the beginning of the drive then install Win XP on the remaining partition, works great and save a lot of headaches.

 

Hold on, take a step back and a deep breath. We don't need to stop this discussion. If you are not going to read the entire thing, at least read the bottom paragraph.

Only because the consumer does not realize it is actually cost effective.

True, most folks would never pay that much for a good drive, but why waste money on an inferior product? Stick with mechanical hard drives if you cannot afford a real SSD.

Probably true, but the end result is failure.

They can fake higher speeds with multi channel architecture, and they can fake reliability with wear leveling tricks and over provisioning. MLC drives may actually be cost effective at some point down the line, but they are not ready yet.

Well if you were a manufacturer getting bigger profit margins, you would ramp up capacity too!

Well I did post a link to one VERY reputable enterprise systems manufacturer that projected any current MLC drive to last 1.2 years in an enterprise enviroment. I guess you missed the link, so here it is again:

Texas Memory Systems - Flash: SLC vs. MLC

I agree with you completely, the vast amount of false statements does place us at opposite ends of the MLC fanclub. I will leave it as it is for the reader to decide who is right.

Considering you NEVER actually posted any relevant links to reputable sources as you promised in your first post, I would hope that any visitors would ignore your personal opinions and go with the facts that I have listed and linked to.

The Kingston Series sells the X25-E and X25-M that are BASED on intel reference designs. As far as I know no one else currently uses their reference designs, but again feel free to post any information.

Try a larger sample size, I am sure there are a lot more than one Sandforce reference layout. I will match your assumption with mine, since I don't really care how many layouts they actually use.

I have rarely seen two components from the same manufacturer with precisely identical components. Unless they were in the same production run, they are probably very different. "Eyeballing" the drives to see if they are identical is a simple rookie mistake. Did you even check the chip numbers to see if they were identical parts? And you base the fact that every Sandforce drive uses the same parts because you opened TWO! My god, whatever happened to common sense, and what do they teach you kids in school these days!

I can't prove that they are lying, but you can't prove that they are telling the truth. Do you think that MLC drives are an HONEST attempt to bring speed and power to the uneducated masses?

If I were running a memory manufacturing company I would produce mountains of MLC drives, not because they are better for my customers, but because they make my company more money than SLC, and the only reason I would have started the business in the first place was to make money!

Please don't be so gullible, any company that is true to its shareholders will do whatever it takes to make money, and MLC drives are currently an AWESOME scam.

I agree, I am perfectly content to leave the decision up to the reader, and hopefully they will discover the truth on their own. Considering there is such a MASSIVE difference of opinion, I would hope that they would do their own research.

I was hoping you would help me discover the truths about SSD drives while we try to educate myself and others, but since you seem content to live in your happy little world I will have to do so on my own. You did not even post a single link to anything other than your own blog! I at least tried to find the facts and correct myself when I was wrong. And I will continue to search for the truth with or without your help.

I spent hours posting information to help you and others, and it looks like you did not even bother to read it. Why? Are you so sure that you are "correct" that you don't even want to see the feast of information that I have laid before you? Ignorance is not do to a lack of knowledge, but due to the lack of trying to learn more.

And if you refuse to try and learn then please don't stand in the way of others that may actually have a chance to save some money and trouble by avoiding MLC drives.

I never read that anywhere, but I guess we should lump SSD drives with religion and politics as forbidden topics.



Since you are never posting again, good luck with all of your endeavors. And I hope your SSD purchasing works out for you, as you seem so proud of your decisions so far. I am happy that you confronted me and forced me to correct some of the worst errors on my main post, but leaving does not help anybody. And it certainly does not help me correct my mistakes and flaws. And since I am human I have many!

Find the biggest error that I wrote, and tell me about it. We can both research that single topic and post our links and hopefully it will help anyone that stops by. At least then we can actually start to learn instead of "throwing" assumptions at each other.

One at a time we can update and correct every single error on this topic. Don't just quit when the going gets tough.

Your turn to post my worst mistake. And then the search for hard facts on both sides can begin.

I look forward to your post.

 

MLC drives are the SSD equivalent of RLL hard drives from the 90s; a workaround to get more storage out of a finite amount of physical media.

In much oversimplified terms, MLC overlays one cell array with another cell array to make multiple layers; this produces more storage than those two arrays could yield in themselves, but it means that to address a single chunk of data the base layer must be addressed as many times as you have additional layers.

If your MLC is arrayed to make an 8GB base layer (The most common arrangement, even today) with 4 additional layers, then to get all your data at one location that base layer must be addressed 4 times, where with an SLC drive it would only take once.

THIS phenomenon is what causes premature failure in MLC drives; and all of Les' bloviating aside, it IS a real phenomenon and NO reputable IT department uses MLC storage in ANY mission critical application.

SLC drives are MUCH more expensive to produce in the sizes today's lazy surf potatoes demand; they are used to being able to buy TBs of storage for less than the price of a business lunch. How can you sell those same fools on a 32GB SSD for $400 or a 64GB SSD for $600, even if it IS faster than greased lightning?

You can't. So you take that same 8GB SSD that you COULD produce to sell for $100, apply MLC trickery to it, and voila - now you have a 64GB HDD you can sell to those same fools for $150 or $200. Add an aggressive bad cell monitoring algorithm and call it "Wear Leveling" and you're good to go, mang.

You can't get something for nothing; the tradeoff here is reliability. If you're just using it to surf the www and check your eMail, then I'm certain almost any MLC drive will provide years of satisfactory results; even if the drive does lose 10-20% of its original capacity over those years due to cell failure.

mnem
You don't ALWAYS get what you pay for; but you DO always PAY for what you get.

 

Ok...last response because the word bloviate was rather interesting.

Perhaps we are mixing up apples and oranges here. I was under the assumption that we were speaking of ssds with respect to typical consumer to include any application you would like to throw at it. Programs such as Acrobat, Photoshop and so on enable the consumer to fully appreciate the ssd and their equipment. To say that the ssd they purchase will last only a year or two is flat out uneducated.

IF we are discussing slc for server and mission critical operations...well I have stated that from my first review in 07. Its simply a given that the server environment is best served by the slc while the cnsumer environment is best served by the mlc. Regardless of the estimate of the TMS video, it is simply a generalization and cannot speak to newer ssds that we are seeing today.

The simple price of SLC NAND makes it impossible for the slc to become a household computer storage medium whereas mlc will do that.

 

So you think that it is acceptable to lose or corrupt a user's data in the interest of profit just so long as it is not a corporate or government computer in question? As long at it's an ordinary citizen who can't afford an army of lawyers to sue the manufacturer, that's allright?

I'm sorry; I disagree. The manufacturers of most digital storage devices have historically (even as far back as those RLL drives of the 90's) taken advantage of the fact that since the technology is evolving at such a fast rate very few people actually understand anything more about ANY storage medium except Bigger is better, faster is better, UGGH!

Seagate almost went bankrupt due to class-action litigation arising from that RLL technology; the ensuing loss of stature in the marketplace is why Western Digital was able to become a household name. Since then every major storage manufacturer has been caught at one time or another knowingly selling drives that fail prematurely; just because they have the money to settle out of court and keep it from being headline news for weeks like every butterfly f@rt that comes out of Redmond doesn't mean it doesn't happen.

They are again marshaling their defenses against similar litigation arising from the high data failure rate of drives using their "perpendicular recording technology", as are other manufacturers who've licensed and others who "reverse-engineered" that technology. This is technology that was released before it was ready; every manufacturer knew it, but they STILL made and sold the drives because of the demand for ever-increasing capacity.

This is not conjecture; this is history and I lived it. Learn from the mistakes of the past and DO NOT trust these people. They will screw you and everything you hold dear for one more decimal point on the EOQ spreadsheet.

MLC SSDs are STILL not ready for primetime. Their flaws are fundamental, and no amount of new trickery will fix that.

mnem
Those who forget the lessons of history are condemned to repeat them.

 

Data integrity is the main reason I use a Toughbook. The price I pay in terms of cost of acquisition and 'performance' is something I am prepared to accept. To further enhance reliability, I have switched to an SSD. After EXTENSIVE research on the web and from other actual users, I purchased an SLC SSD. It costs more than twice the price of an MLC unit of comparable size.
As usual, mnementh is right on track, no amount of engineering gimmicks or slick marketing can overcome the physical characteristics and limitations of flash technology.
I suppose that in the interest of openness, there is no way to discourage posters with an obvious agenda and a website to push, from participating in this forum, but I for one, wish they would shill their views and wares elsewhere.