Samsung PM800 256GB SSD Tests

Hey guys,

Could those of you who have one of these drives do a test with CrystalDiskMark 3 (using averages of 5 tests and 1000MB) and report your scores.

I remember initially when I had my lappy and SSD I was getting read/write speeds of 210+ MB/s and 170+ MB/s respectively (sequential), and for 512K files the speeds were ~170 and ~130. However, that was with a test of 100MB chunks. I'm sure I would have gotten the same results though with 1000MB chunks. But recently I've been experiencing a huge decline in performance, and when testing with 1000MB chunks I still get read rates of ~200MB/s but write rates of 10-12MB/s (sequential that is!).

So I was curious what you guys are getting? Thanks!

Ah yes I'm running the old non-TRIM firmware (VBM19D1Q).

 

Firstly, I wouldnt be using the 1000MB test as every test writes 1000MB to your drive. Just use the 50MB test as results will still show gains/losses.

Secondly, it is most likely the fact that you dont have TRIM that this is happening.
How full is the drive?
What are your 4K read/writes like?


You may want to check out this thread

 

Well, on average I've probably written at least 20GB on this drive for a year now. So a few 1000MB tests won't really change things too much. And the reason I'm opting for 1000MB tests is that I seem to be having stalls and slow downs when larger chunks of data have to be written in one go. That's both when transferring data, extracting/compressing large files, etc. The first few 100MB's are ok, happening at around 100-150MB/s, but then the system seems to stall and that can last for 10seconds up to several minutes, before continuing the next chunk.

And my 1000MB test results seem to confirm that:

 

Is it possible to update a PM800 SSD drive on a XPS 1645?
I'm getting lower speeds on my drive and the update are perfomance related, but the XPS 1645 are not mentioned in the update... Drivers and Downloads
What is the safe way of doing this?

 

Seriously, running 1000MB tests on a non-TRIM drive are really going to kill your write performance, the 50MB tests should give you the same results. It fills up your drive with garbage, and there's no TRIM to clean it up.

 

Sorry I wasn't that precise I have the firmware VBM24D1Q, so TRIM are enabled, btu I still get lower speeds 15% lower read and around 30% lower write speeds.
I have installed the newest Intel Rapid storage technology.
I have only been running the speed test twice and are only using around 35gb of the 223gb.
Information is a good thing

 

how much of the ssd space have you used out of 256gb? after you start inching over 50% on the way to 70% it will go slower and slower

 

Only around 37gb, so it shouldn't be the reason...

 

I think its not very accurate to judge drive read/write speeds on tiny 50MB data transfers, but its much better to take the average read/write speeds over a bigger section transferred. Especially when doing over 20GB of data transferring daily, sometimes even a 100GB. Furthermore when only doing 50MB transfers its not very easy to spot a fault when a transfer stalls for a few seconds after having transferred the first few 100MB, as was the case with mine.

Of course when not having TRIM-supporting firmware its not a great idea to transfer such amounts on a daily basis...

 

I don't think that necessary true with SSDs. There's no speed difference from the beginning of the drive and the end of the drive like on an HDD. Also, with SSDs the data is stored spread out through the drive, so even a 50MB file is likely to have a piece of it stored in every chip on the drive, testing the entire thing.

The reason why you're slowing down when doing 1GB transfers is because it's running out of cleared write space to put the files. Data on a SSD can't be overwritten like it is on a HDD, so before you write to it is has to clear any existing data already present in the destination cell, which takes a long time and severely slows down the drive. With TRIM, the OS erases the data and clears out the cell making it ready to write again using idle time soon after deleting it, but without trim the old data from the deleted file (called garbage) just stays there until the drive's firmware eventually finds it, slowing you down if you try to write before it's cleared. Testing 5 1GB files leaves over 5GB of this 'garbage' lying around on your drive, slowing down any further tests that you do.

I'm not too familiar with the Samsung drives, but whatever garbage collection that they use likely only clears a GB or 2 at a time to keep drive wear down to a minimum (data on a SSD can only be cleared a finite amount of times), so using more than that (like 5x 1GB tests) will slow you down, but that's not a problem, it's the drive's design.

Also, if you're transferring 20-100GB a day on your SSD, you're going to wear it out quick. SSDs are not designed for that kind of workload. Each NAND cell on a SSD only has a finite amount of write cycles before it burns out completely. Filling up 10-50% of the drive every day will wear it out completely in under a year. For a workload like that you're better off getting a traditional HDD.

 

Here's my results on a PM800, your Sequential and 512k read speeds look close to normal the rest are way off especially all of your write speeds, anyway on to the screen shot:

 

Interesting, especially the part where you talk about cleared write space. That app you mentioned in the XPS 1645 thread clears that write space (via secure erase?).
In any case getting the drive replaced with one that does support firmware is the best option I think. And to get some confirmation clearing the write space of performing erases on a trim-supporting SSD is not necessary anymore then I gather?

 

Yes, secure erase tells the drive to clear every cell. Make sure that after you send the secure erase command, that you leave the drive powered on for about 15 min before you restart (the secure erase command is issued instantly, and it looks like you're done, but the drive is working internally still).

Yes, if you have TRIM, you shouldn't have to worry about this, as when a file is deleted Windows sends a command to the SDD to clear the cell when the drive is otherwise idle.

 

Just a quick FYI, I did this firmware update earlier in the week on my SXPS 1645, and it works great. My write speeds are 50% faster now. Just make sure your firmware is listed as compatible. I believe only the one ending in a 15 is too old to update.

 

I did the firmware update on the 128gb PM800 drive that came in my XPS 1340. World of improvement. It's not the laptop that's the determining factor just the SSD it self.