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256GB SSDs x2: To RAID 0 or not to RAID 0?

Posted: Sat Apr 14, 2012 2:18 pm
by cynan
I'm in the process of a new build and have picked up a couple of the Corsair Performance Pro 256GB SSDs.

Considerations:

1) Capacity: 256GB is enough capacity for a boot drive, but my preference would be to have a single 512GB drive. Winner: RAID 0

2) Performance: I'll be using the storage controller on the X79 chipset, so I don't know if a RAID 0 setup will provide better performance over a single drive; I can't find a single test on the internet of 2 Corsair Performance Pros in RAID 0. Winner ?

3) Long-term performance: Still no TRIM support yet for Intel RST. However, these Corsairs seem to have pretty aggressive garbage collection, so I'm thinking I'd be fine for a while... Winner ?

4) Data security: The system will not be storing any critical data on the boot drive. Plus I'll probably make backup images regularly on mechanical storage. Winner: Single Drive, but meh...

I guess I can just try it both ways and see if the RAID 0 offers any performance gains or pitfalls compared to single drive. However, if anyone has any experience with newer SSDs and RAID 0 with the Intel storage controller, it would be nice to hear from you. I certainly wouldn't be willing to trade poorer performance just so I could have a single 512GB boot drive.

Re: 256GB SSDs x2: To RAID 0 or not to RAID 0?

Posted: Sat Apr 14, 2012 3:10 pm
by mac_h8r1
I don't have a reference ready to shove at you, but I don't think the X79 would give you RAID-0 speed benefit. I'm using a Highpoint RocketRAID PCIe x4 adapter to RAID a pair of SATA3 OCZ drives. It is STUPIDLY FAST.

I'm also smart enough to have daily backups to a Windows Home Server (and like you said, no critical data).

Until a benchmark shows that the X79 gives more than 1.5x performance increase for Sata3 SSDs, my vote is for single drive.

Re: 256GB SSDs x2: To RAID 0 or not to RAID 0?

Posted: Sat Apr 14, 2012 3:27 pm
by Firestarter
I would keep the drives separate. If you get in some trouble with one drive filling up and the other being empty, you can always move stuff around a bit at ridiculous speed.

Re: 256GB SSDs x2: To RAID 0 or not to RAID 0?

Posted: Sat Apr 14, 2012 3:49 pm
by UberGerbil
What is the purpose of this build?

Re: 256GB SSDs x2: To RAID 0 or not to RAID 0?

Posted: Sat Apr 14, 2012 4:13 pm
by End User
cynan wrote:
I'll be using the storage controller on the X79 chipset

Which MB?

Re: 256GB SSDs x2: To RAID 0 or not to RAID 0?

Posted: Sat Apr 14, 2012 7:37 pm
by frumper15
I don't have the X79 or even SATA3 connections on my P55 mobo, but I have two 128gb M4s in RAID0 as we speak. Not because I needed to or necessarily because I wanted to, it was more or less that newegg had the M4 for crazy on sale and I had just sold one of my mechanical drives. Anyways, I put the extra drive in, updated firmware to the most recent to match the existing drive and used the intel software to migrate to a RAID0 array (one of my favorite features of the intel software). Then I had to RAID a pair of Samsung F3 1tb drives just to attempt to make some transfers approaching the limit of the drives and the SATA controllers. I won't lie - seeing files transfer at 350+ mb/s brings a huge smile to my face, but as far as a performance increase? Not really - the drives are pretty quick all by themselves.

If you need 512gb of blazing fast SSD storage, you won't regret it; but if you're like me, it will be a fun exercise in excess but will find you'll be better served re-purposing the 2nd drive in another machine that doesn't have an SSD (I'm thinking my laptop) or break the RAID and have a separate drive for some other reason.

So, my vote would be make a backup of your existing setup, Migrate to a RAID0 array using the intel software, get yourself some big grins and then decide if it is worth the $$ invested for the performance you get and whether you keep it that way or not. If not, restore from backup.

Re: 256GB SSDs x2: To RAID 0 or not to RAID 0?

Posted: Sat Apr 14, 2012 8:31 pm
by morphine
Geoff recently did an article analyzing the RAID-0 proposition with SSDs (I can find the link if you want). Bottom line: if you do that, you'll end up hurting performance overall in the mid/long run, because you'll lose TRIM.

Re: 256GB SSDs x2: To RAID 0 or not to RAID 0?

Posted: Sat Apr 14, 2012 8:38 pm
by ImSpartacus
Today's SSD RAID is a short term performance bump in exchange for a long term performance pain in the ass.

Re: 256GB SSDs x2: To RAID 0 or not to RAID 0?

Posted: Sun Apr 15, 2012 12:24 am
by wirerogue
i like this article at xbit

http://www.xbitlabs.com/articles/storage/display/kigston-hyperx-ssd-raid0.html

there are definitely pros and cons.

also, it is only write speed that can degrade over time.

Re: 256GB SSDs x2: To RAID 0 or not to RAID 0?

Posted: Sun Apr 15, 2012 3:00 am
by Voldenuit
morphine wrote:
Geoff recently did an article analyzing the RAID-0 proposition with SSDs (I can find the link if you want). Bottom line: if you do that, you'll end up hurting performance overall in the mid/long run, because you'll lose TRIM.



The Corsair Performance Pro's idle garbage collection works as well as TRIM. I say go for the RAID-0.

Re: 256GB SSDs x2: To RAID 0 or not to RAID 0?

Posted: Sun Apr 15, 2012 5:55 am
by vargis14
I would also keep then separate,they are plenty fast alone and having different programs especially if they are HD intensive programs on 2 separate HDs will allow you to run 2 HD intensive programs at the same time without a slowdown. Well at least a minimal one.
They are fast enough alone,i do not think they have to hold hands:)

Re: 256GB SSDs x2: To RAID 0 or not to RAID 0?

Posted: Sun Apr 15, 2012 6:43 am
by Firestarter
vargis14 wrote:
I would also keep then separate,they are plenty fast alone and having different programs especially if they are HD intensive programs on 2 separate HDs will allow you to run 2 HD intensive programs at the same time without a slowdown. Well at least a minimal one.
They are fast enough alone,i do not think they have to hold hands:)

Well thats a misconception if I ever saw one. We're talking SSD's, remember? Running 2 intensive operations concurrently on a single SSD will not slow the operations down significantly. In fact, I bet that for a majority of what we would typically do, the operations would finish sooner if you'd run them all at the same time, rather than waiting for each operation to finish before starting the next. For traditional spinning platter drives, that is most certainly not the case.

Re: 256GB SSDs x2: To RAID 0 or not to RAID 0?

Posted: Sun Apr 15, 2012 7:30 am
by vargis14
I could not agree more,SSDs can handle 2 HD intensive programs a heck of alot better then a platter but i think if those 2 HD intensive programs are on different SSDs it just seems logical that they would perform faster then on one ssd.After a quick google search i cannot find anything to back up my statement,but it does not sound unreasonable to me.
Plus you have the added protection of having 2 separate drives in case one of them fails.You cannot call that a misconception.

Re: 256GB SSDs x2: To RAID 0 or not to RAID 0?

Posted: Sun Apr 15, 2012 7:57 am
by 5150
I've done a lot of messing around with RAID 0 and SSD's, two, four, onboard RAID, Adaptec RAID, my conclusion is simple.

It's fun and fast if you want to mess around, but in my opinion, it's not that fast or that fun compared to a single drive when you consider the PITA it can be.

Re: 256GB SSDs x2: To RAID 0 or not to RAID 0?

Posted: Sun Apr 15, 2012 9:09 am
by morphine
Voldenuit wrote:
The Corsair Performance Pro's idle garbage collection works as well as TRIM. I say go for the RAID-0.

Although those results are interesting in themselves, in that review they didn't actually RAID the drives. Geoff's SSD scaling review (link to first results page) shows what happens when that is done. It's especially painful for the RAID sets in the file copy tests, as the used state results are abysmal for the most part. And in boot and level load times the results are pretty much a wash.

Re: 256GB SSDs x2: To RAID 0 or not to RAID 0?

Posted: Sun Apr 15, 2012 11:09 am
by Voldenuit
morphine wrote:
Although those results are interesting in themselves, in that review they didn't actually RAID the drives. Geoff's SSD scaling review (link to first results page) shows what happens when that is done. It's especially painful for the RAID sets in the file copy tests, as the used state results are abysmal for the most part. And in boot and level load times the results are pretty much a wash.


The real-world copy tests show an advantage for the crucial m4 RAID-0 drive, although it has abysmal tortured state results. Considering the m4 has lousy garbage collection compared to the corsair performance pro, you can expect the RAID-0 performance of the Corsair Performance Pro to be better than the RAID-0 fresh state of the m4 since it's also a faster drive.

Re: 256GB SSDs x2: To RAID 0 or not to RAID 0?

Posted: Sun Apr 15, 2012 12:20 pm
by JohnC
cynan wrote:
my preference would be to have a single 512GB drive

Sell your 256GB junk, get a fast single 512GB drive. I've been using my Crucial m4 512GB single drive for a few months (as my primary drive for almost everything, including games) connected to Intel's SATA3 controller, completely satisfied with its performance and so far never felt the need to buy another one for RAID0 setup.

Re: 256GB SSDs x2: To RAID 0 or not to RAID 0?

Posted: Sun Apr 15, 2012 5:04 pm
by cynan
Thanks for all the feedback :)

The problem with most SSD RAID 0 articles on the net (including Geoff's) is that it is not that relevant to RAID arrays of 256GB SSDs and larger.
Most SSDs that I'm aware of don't scale much past 256GB as far as write speeds like they do between smaller capacities (IE, the Samsung 830 has an advertised write speed of 320MB/s for the 128GB drive, and 400MB/s for both the 256G and 512GB drives). So while I would probably agree that using a single 256GB drive over 2x 128GB drives RAID0 is not worth it for performance, 2x 256GB RAID 0 vs 1 512GB is a different kettle of fish.

The second problem with SSD RAID 0 articles is that the few (like this one) that have done extensive RAID 0 testing that I've come across use $$$ hardware RAID controllers. So while the above article definitely shows performance gains for drives like the 256GB M4 and Samsung 830 in RAID 0, I don't know if I'll see anything close to this using the Intel X79 controller (board is Asrock Extreme6, but I don't see what difference brand should make - I'd be using the two sata3 ports on the Intel controller which should be the same across all X79 boards).

Third, I've read that the garbage collection on the Performance Pros are quite aggressive and should mitigate the lack of TRIM, at least for a long while. Even Corsair recommends these drives for RAID arrays due to this feature - but perhaps this is just marketing.

Finally, there's a single Newegg review for the Corsair Performance Pro 256GB that claims to be "loving them" on his X79 in RAID 0. And you just can't argue with that kind of hard evidence :P

So, since I have the 2 drives, I'm leaning toward giving them a try in RAID 0, for a while anyway. Now all I have to do is figure out how to build the array so I can do a fresh Win 7 install. I've been reading that using a flash drive with a Win 7 image and up-to-date Intel RST drivers is the way to go. Apparently people have been having issues with getting the RST drivers to install off of a separate flash drive when installing Win 7 from a DVD...

Re: 256GB SSDs x2: To RAID 0 or not to RAID 0?

Posted: Sun Apr 15, 2012 6:23 pm
by ShadowEyez
I'll vote against the grain here, for Raiding it up. I have a similiar situation: 2 240 gig agility 3 drives, on my Asus P5Q and they are running raid0 via intel rst right on the board. Win7 64bit sees them as a one drive. It's a little (though not a lot) faster in RAID with my informal testing and more streamlined to manage just a "c" drive than a "c and d" drive. And yes, do back everything up.

Once intel comes out with their rst 11.5 I'll update to that for the TRIM support on RAID, though with the agility/sandforce, it does pretty good garbage collection internally. And yes, it feels fast.

In the end, the raid approach requires a little more work up front when installing the OS, less day to day stuff of shuffling files between a C and D drive, and a little bit of thought on system upgrades, OS reinstalls, full image backups etc...

One other thing of note: if you're going the RAID route, do make sure you have a working boot/rescue cd - for instance, system rescue cd and knoppix take a little fiddling with to mount the RAID. I would suggest if you do RAID and get it set up, boot into knoppix/system rescue/what ever you want when it's not an emergency to make sure you can and know how (know the mdraid or dmraid commands, know what mobo/raid card drivers need to be on the disk etc...), rather than finding out you can't even mount/see the disk in the panic of trying to fix a borked system or rescue a few files.

Re: 256GB SSDs x2: To RAID 0 or not to RAID 0?

Posted: Sun Apr 15, 2012 8:14 pm
by Waco
I recently switched from a pair of 128 GB Vertex 3s in RAID 0 to a single Corsair X128 (running the newest Indilinx 2142 firmware from Supertalent) as an Intel Smart Response cache drive for an old Seagate 7200.10 750 GB HDD. There's literally no difference in real world use after the first few times you do anything.

So on that note, I would bet you probably won't see any real difference in performance between a single drive and two in RAID 0. I used to rave about how fast my array was...but if what I'm running now is subjectively identical it's hard to justify the increased complexity. :P If you're going to RAID the drives do it for the space alone, not for any increase in performance. :)


EDIT: For installing Windows 7 on the array...I didn't have to add any drivers or anything for the installer to see the array. I'm using the newest media refresh.

Re: 256GB SSDs x2: To RAID 0 or not to RAID 0?

Posted: Mon Apr 16, 2012 5:00 pm
by Airmantharp
Problems with installing Windows from a DVD are fixed easily by using a flash drive, on which you can also put the necessary drivers. It's considerably faster to boot.

Re: 256GB SSDs x2: To RAID 0 or not to RAID 0?

Posted: Mon Apr 16, 2012 5:56 pm
by geekl33tgamer
I've raid 0 my 2 SSD's, but that was only for space reasons (as they are cheapy, old SSD's now). Seq read and write is naturally better with them in raid 0 too, but you dont really notice it in day to day use IMO. The biggest advantage is the random seek times, and single disk or not any SSD is 8x or more better than a mechanical drive at this, and it's this performance increase you notice.

Edit:
Image

My Patriot drive's are no Sandforce, but im happy with this and still say raid 0 them (as long as those drives have a trim-esque garbage collection algorithim)...

Re: 256GB SSDs x2: To RAID 0 or not to RAID 0?

Posted: Mon Apr 16, 2012 7:43 pm
by UberGerbil
rcs2k4 wrote:
Seq read and write is naturally better with them in raid 0 too, but you dont really notice it in day to day use IMO. The biggest advantage is the random seek times, and single disk or not any SSD is 8x or more better than a mechanical drive at this, and it's this performance increase you notice.
But random seek times are near-zero for SSDs whether you RAID them or not. So there's no advantage to RAID there. This is why I asked what the OP's intended usage was: if it's something that is primarily latency-gated, then RAID isn't going to make any difference. Putting the two drives into RAID is only going to offer a performance benefit if the OP needed STR throughput greater than what one SSD can provide, and in non-server scenarios there aren't many of those -- even heavy raw video editing is unlikely to be an issue, and 512GB probably isn't enough space for that anyway. There are other reasons to combine the disks -- to make them appear as one volume for simplicity's sake, for example, though in that case I'd look at alternatives (ie redirection) that don't force you to give up TRIM.
My Patriot drive's are no Sandforce, but im happy with this and still say raid 0 them (as long as those drives have a trim-esque garbage collection algorithim)...
Not to pick on you in particular, but I wish people wouldn't talk about TRIM and garbage collection like they're interchangeable replacements for each other. Even the best garbage collection algorithm might be useless when it has no garbage to collect, because it doesn't know which blocks are garbage, because the file system can't use TRIM to tell it what blocks actually contain disposable data from files that have been deleted. No matter how good the garbage collection might be, you're eventually going to need a mechanism that can pass that file-system-level knowledge down to the SSD controller or you will see write performance drop.

Re: 256GB SSDs x2: To RAID 0 or not to RAID 0?

Posted: Tue Apr 17, 2012 9:36 am
by Waco
rcs2k4 wrote:
Edit:
Image

Those 4K results are terrible for an SSD let alone a pair in RAID 0. Have you updated the firmware of your drives? The newest one seems to help a bit: http://www.servethehome.com/patriot-ps1 ... are-v3000/

UberGerbil wrote:
But random seek times are near-zero for SSDs whether you RAID them or not. So there's no advantage to RAID there. This is why I asked what the OP's intended usage was: if it's something that is primarily latency-gated, then RAID isn't going to make any difference. Putting the two drives into RAID is only going to offer a performance benefit if the OP needed STR throughput greater than what one SSD can provide, and in non-server scenarios there aren't many of those -- even heavy raw video editing is unlikely to be an issue, and 512GB probably isn't enough space for that anyway. There are other reasons to combine the disks -- to make them appear as one volume for simplicity's sake, for example, though in that case I'd look at alternatives (ie redirection) that don't force you to give up TRIM.


Well that's not entirely true. Random seek bandwidth (for reading or writing) is substantially faster with a pair of drives versus a single drive...as long as your queue depth is higher than 1. That last bit is the caveat. If you do like to load your system down by doing multiple disk-intensive things at once a pair of drives in RAID 0 can actually provide a decent increase in throughput.

Re: 256GB SSDs x2: To RAID 0 or not to RAID 0?

Posted: Tue Apr 17, 2012 3:34 pm
by geekl33tgamer
Waco wrote:
Those 4K results are terrible for an SSD let alone a pair in RAID 0. Have you updated the firmware of your drives? The newest one seems to help a bit: http://www.servethehome.com/patriot-ps1 ... are-v3000/

Thanks for the article, but when I checked the drives with Patriot's firmware flasher it was on the latest release anyway. Looking at the linked article, my results on the latest firmware are comparable to theirs. My 4k read is slightly higher than theirs, and my 4k write is slightly slower. I guess this performance is about right for this SSD.

Like I said, they were cheap, they are about 2 years old, and definatly already on my upgrade agenda... This gerbil's piggy bank plumped for my Bulldozer 2 months back, and is almost at breaking point for a single 256GB Samsung SSD now. That drive gets fantastic reviews. :wink:

Re: 256GB SSDs x2: To RAID 0 or not to RAID 0?

Posted: Tue Apr 17, 2012 4:54 pm
by Voldenuit
Having weighed in earlier with a vote to RAID-0 the drives, I read this article today:
http://thessdreview.com/ssd-guides/beginners-guide/garbage-collection-and-trim-in-ssds-explained-an-ssd-primer

Although it's obvious in retrospect, the article explains that idle garbage collection consumes more write cycles than TRIM. This is because the drive doesn't know which cells are inactive (deleted) when using garbage collection alone, so will block rewrite a lot of redundant data when it performs TRIM operations.

I doubt that longevity will be an issue with RAID-0. Marvell drives tend to have low write amplification anyway (although not as low as Sandforce), but with the sheer variety of custom firmwares for each OEM, it's hard to generalise on behaviour. It's still something to consider, though.

If I were setting up a system for myself, I probably wouldn't go through the hassle of RAID-0, but then I'm not after bleeding edge performance (emphasis on bleeding). Compatibility with live CDs and recovery tools would be very important. I agree that having a single big 512 GB drive is a lot more convenient than having 2x256 GB drives, but with the use of libraries and junction points, this can be worked around (albeit, still not very elegantly).