Seagate Momentus XT Hybrid HDD w/ built-in 4GB SSD

I'm not sure if that's still true with SD28.

http://forum.notebookreview.com/har...brid-hdd-w-built-4gb-ssd-176.html#post7913803

 

My results after SD28



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@Phil, the update was probably focusing on the SSD portion.

 

@ Hungry man, Crystal Disk Mark works with random data. These files can not be cached. If these files were coming of the cache we would be seeing very different numbers.

 

Why can't it be cached?

I mean, if you run the test 10x in a row you'll see a difference.

 

As far as I know the data is randomly generated before each run. As you probably know it will only cache data if the same data is read several times.

I just verified it. Ran it ten times. Besides some normal fluctuations, there is no improvement.

It also makes sense, 0.6 MB/sec 4K random read is a score of a platter drive, not an SSD.

 

Hm, alright thanks.

 

Well, after 3 days running with the XT's in raid0, I am going back to the Scorpio Blacks.

I am getting some nasty hesitation when switching between VM's and especially after 3 or more VM's have been running for a few hrs or more. I never experianced that with the Blacks.

Dont know what causeing it, but I know I dont like it.

 

Maybe now we found the reason why Seagate does not recommend running them in RAID.

 

Yup Yup, I would agree with ya there. It was a nice try, and TBH performed well for a bit there but somehow something got out of sync and its ugly. I think I am confusing the cache.....

 

wwoods,

That was with SD28 [FW] on the XTs and Intel RST 10.6.0.1002, correct?

 

That is correct sir.

 

I'm happy to see that the theory finally meets the practice

I will also consider updating to SD28.

 

huh ?........did I miss something ?

 

I believe he means that the XT is finally performing the way we'd all hoped when we first heard about it.

 

Hehe, sorry wwoods, that wasn't very clear

First i meant that theorically, it was obvious that the XT in RAID was neither a bad idea, nor a good one. It wasn't designed to work that way and the NAND cache wouldn't bring - in my opinion - a real speed gain in RAID compared to a normal 7200rpm. The experience shows that the theory was quite exact. So i was happy to see that i wasn't completely off topic. That's it.

Then, apart from that, i was saying that it may be time for me too to update to SD28 (im using it on a laptop).

 

I think where a lot of confusion for the RAID on the XTs comes in is from tech articles/reviews. These place the XTs in a RAID configuration, test it for a few days, and then say... yes, it works. It's great! Here are my findings...

For instance, take this quote:

Sounds pretty good, doesn't it. But my guess is this was a RAID volume for the system files, not tested in other configurations, like a test with very large files. It may work, but wwoods testing says otherwise.

Now, wwoods does not say how big each of the VM files are, but if he's like me, it is safe to assume they are at least 4GB in size. My largest is 85GB. So, when 3 or 4 are all accessed at the same time, there might be some other kind of performance penalty because most likely the NAND portion of the drive is most likely used with that many large files (or a portion of those files). Also, was virtual memory in play here? What stripe size was used? (What would be optimal to work with the SSD portion?) Was context switching that occurred when switching VMs paging memory in/out causing a possible pause? Where did that pagefile exist - on the RAID volume or SSD disk? Maybe someone else could get this to work, but there may be a lot of required tweaking.

Regardless, RAID-wise, about the only thing I'd recommend for the XTs is RAID-1. Someone *might* be able to get things up and running on RAID-0 in a system boot type of situation, but 1GB is a lot of space to waste if you use large files. In regards to RAID-5, it may someday work with tweaking of power settings on the drive with AAM, but for general out of the box use, RAID-1 has not caused me one iota of a problem.

 

And RAID 1 is mirroring. So you get the same data of both disks. So you should, after a time of use, get the same cached chunks on both NANDs. Then I think the NAND would come into play again here and work pretty well.

Anyway, if your VMs are all running at the same time, you are stilll, as you mentionned, too limited by the 4GB.

 

Thought I would follow up on this, after switching back to the Scorpio Blacks, been running like a champ, no hesitation at all. As for the size of my VM's they run from 20G to about 45G. I useally have 2 running at a time, but once and a while as many as 4.

I cant say what the issue was/is with the XT's, but I dont experiance it with the WD's. All I can surmise is that the cache was "out of sync" somehow.

 

A point of clarification, I believe the SSD portion of the XTs works for ALL RAID configurations. Nothing any review or whitepaper suggests otherwise.


wwoods, if you're up for one more test, I have an interesting one. If there is enough room, what happens when you run the same VM test as your RAID-0 XT based volume, but instead of any RAID volume, use just a single XT. Same pauses? If so, then it is not necessarily the RAID that is the problem, but rather the size of the files.

 

INteresteing idea....I am running the same VM's right now on the Scorpio Black Raid0 that caused the hesitations on the XT Raid0, and am getting no hesitations at all.

I will consider that Idea, but it means a reinstall of the OS and reconfiguration to non-raid...

 

Yes, a big pain, but what it would answer the question is the size of the files the problem or is it the RAID volume.

Would you have to re-install the OS? I don't know if you have any system files/resources on the RAID volume, but could you
a) copy the VMs somewhere
b) remove the Scorps
c) boot
d) In BIOS, remove any RAID volumes
e) Reboot into windows
f) Removing any drive volumes.
g) Re-boot to make sure system is OK.
h) Shut down
i) install a single drive
j) boot
k) initialize/format the XT
l) copy over the VMs
m) retest.

Wow, I take everything back. That is a lot of steps!!

 

Well, I have no plans to go back to the XT's in my Raid0, but, I have a week of vacation comming up here soon and may give this a shot. Will be interesting to see the outcome.

So been thinking about this, I will probably do the tests, I use Macrium reflect as a backup/image solution so the backups/images will be cake. I expect I can pull this off in a day if I dedicate myself to it, so yea you can expect me to run these test. Not sure on a ETA yet though.

 

Of course the SSd works all the time. One more time: i'm not saying the opposite. I was speaking about the "usefulness" of the NAND in such configuration. I should've wrote "NAND benefits come into play again", and not "NAND comes into play".

I'm also very interested in the test that will try the single XT against RAID XTs on the 4-VM system. I'm betting the desync won't happen again, but only the test will show it.

 

I see. However, I think RAID-0 for the XTs might work in certain situations. Perhaps a end-point location for system files / and a lot of read-only files might be a big win for certain users. Then again, there are better ways to achieve the speed of SSD (like SSD itself) and a bit safer than using RAID-0.

 

Heya kinda off topic from Raid0, how is your speed with the Raid1 on your XT's ?

 

I don't have anything to compare it to, but I do not have any complaints. The drives just work.

If you have other benches against this drive, perhaps that would help:

 

No idea either. All I know is that my dual-XTs work just fine in Raid0 here.
Of course, YMMV.

I doubt it.

 

Pirx,

Are you running VMWare or Virtual Box? If so, what size are your VMs, and on what laptop system are you using the XTs? We're trying to find out the impact (if any) on the XTs when dealing with 15GB to 20GB files.

 

Just took a look at file sizes, I go from 20GB - 90GB for biggest VM, VMWare Workstation8.

 

No, I don't much use VMs at all, and I have no current data on loading large VMs. The laptop is a Dell Precision M6400, maxed out everything in case it matters.

I am trying to remember, I used to have some rare occurrences of the system hesitating during disk reads a long time back, but I'm not entirely sure anymore what fixed the issue. I think it was related to write caching settings in Win7. When I had these issues, they were accompanied by event log errors (timeouts) from the disk subsystem. Do you see errors in your event log? Like I said, I haven't seen these errors in the last year or so. They might have been related to the version of the Intel drivers I had been using then, however.

 

Thanks for the clarification.

Do you think my earlier statement is correct?

Also, do you have any real world data that could address Ninj's post: "the NAND cache wouldn't bring - in my opinion - a real speed gain in RAID compared to a normal 7200rpm." Any chance you've run some benches in a before/after configuration? What are your boot times like?

 

Yes, I think that earlier statement of yours is correct.

I don't have any hard benchmark data available, but my boot times are a lot faster than you would typically see from a standard 7,200rpm drive. If I remember correctly, my boot times with standard 7,200rpm drives were in the 50-second range, whereas with the XTs I'm down to 30-40-ish seconds (mind you, this system has a boatload of software installed, and loads a ton of stuff at boot, with about 2GB of memory used on first login). The system boots faster than a newer M4500 with a single XT I have, which loads less software and runs on a faster processor. In fact, in many situations the system feels similarly fast to that M4500 running on an SSD (Crucial M300, which I had in there for a while, before going back to a mechanical HD). Not quite as fast, and not always, mind you, but intuitively I would say the M6400 with dual XTs in RAID0 is roughly halfway between an SSD-based and a mechanical-HD-based system. Not a bad deal at all for the money, if you ask me.

 

Question for ya, have you noticed, in your raid1 configuration, it gets a tad bit warmer ?

 

Nothing to measure against, but I don't believe the system runs any hotter than if there were two other platter based HDDs in the system. To me it seemed my old NP9860 ran a bit hotter w/ 3 HDDs in RAID-5.

 

Aneother question if I may, when ya have the raid1, in RST you have the option to "initialise" it. Now, in a raid5 I understand why you do that, to calculate the parity, but since a raid1 is a strict mirror, whats the reason for initialisation, I cant fathom the reason in a raid1.

I also see the Intel RST also offers a "Recovery" option, from what I can find on the net, its like a more flexible raid1 ? anyone have experiance with that ?

 

In any RAID setup, you need to synchronize the drives (that is why identical HDD models give the best results...). Initialization in RAID1 is what does this 'sync'.

 

Ahh, thankya thankya.....appreciate that info

 

Dunno about the initialization. It might be something that the driver writes out to the drives to show they are both sync'ed and participating in the RAID volume. So, if the driver looks at those stamps and they are different, then the driver would know one drive is not the mirror of the other, and the RAID volume is degraded. Note, this is just a big wild a@@ guess.

In regards to "Recovery", from what I can tell, Recovery is what RST calls RAID-1. RAID-0 is called "Optimized."

HTH

 

It seems like last 10 pages are 80% about RAID. Nothing wrong with that it's just not that interesting for everyone. If anyone wants to discuss RAID for Momentus XT further please make a new thread.

 

Thats my fault......started off by talking about SD28, and then I brought up Raid1 / Raid0 with those things and it took a life of its own. Probably because I had such a smashing experiance with them in a raid5 many moons ago.....

anyway...subject dropped

 

Ok so i just found out my replacement alienware apparantly has this drive. I barely notice any difference from my old laptop's 7200rpm drive. Is there a way to optimize this hard drive for quick boot times?

 

Make sure you have firmware SD28. Reboot three times and measure with boottimer.exe.

The Xt boots about 20% faster than a 7200rpm drive.

 

technos, I agree: first upgrade to the SD28 Firmware version.

Then, 'shrink' your C: O/S partition to as small as possible (100GB is very, very large for most people). With the 'extra' capacity now available, create another partition and move your folders inside the C:\Users folder to the new drive (most likely E:, if you have an optical drive installed...). This will allow you to have the use of all your capacity of the drive.

With a 'short-stroked' C: drive partition - your system will be as responsive as it can be, including booting up noticeably faster (after a few reboots, as mentioned...).

How can you do the above method 'better'? Clean install Win7 and move the Users folder (not the same thing as moving the folders inside the Users folder...) to the D: drive. What this will achieve is possibly making C: drive as small as 50GB (or less) and really making your system almost as responsive (day to day use...) as an SSD.

See:
http://forum.notebookreview.com/7960753-post50.html


Good luck.

 

I agree

Did that myself (my Win partition is 64GB and only 50% full), Users are on D:, i get amazing boot times.

I have a huge bunch of services loading at boot. Everything you can find on a development machine + a personal machine (86 processes running anytime), and my Windows loads in 1 min 20 s. Very happy with that

The important part is to do a fresh install of Win 7 with the trick to get Users folder moved before it installs. Google it, there are plenty of posts on that subject. It's all about opening a console at installation time, rebooting on administration interface before it actually install files, change some settings, and finish the installation. That's the cleanest way possible.

I'm running out of time for now, but i might come later and give you a link if you wish.

 

Worth mentioning here as well:


to discuss the new model: http://forum.notebookreview.com/har...eagate-momentus-xt-750gb-w-8gb-nand-more.html

 

LOLWUT? Am I seeing that right? 8GB NAND on a 750GB HDD? 9.5mm assuming? Awesome. Now we're talking. Just wish they would give users more control of what they want to use the NAND for.

edit: nevermind saw the link for the discussion, and good to see it's 9.5mm.

 

For my daughters machine I just formated out as full for the c:\ drive. Yes it can be more optimized but I rarely touch her machine so the simplist setup is best. Still way faster at booting etc than the old 320 GB 5400 RPM drive.............

 

First post here, bear with me and sorry for the dramatic red/bold

One change I did notice since my SD26 upgrade to SD28 on my Momentus XT: cache/buffer seems reduced or simply reported reduced to 16MB, that is just after flashing the firmware, as one shutdown later there was no more information about buffer/cache.

I add just used AIDA64 and CrystalDiskInfo (which made me wondering if a new firmware was there) before flashing and I was pretty sure it was reported at 32MB.




After a complete shutdown and restart : I got "Unknown"




Did anyone have seen that, or am I just seeing things?

Cheers.
meme

 

Yep, I posted on it about a year ago: http://forum.notebookreview.com/win...gramdata-folder-separate-drive-partition.html

In any case Users folder doesn't need to be moved before install, just move the contents to another partition or drive once Windows is installed if you don't want to deal with the pre-installation environment.