SSD's and Raid 0

[Tim]

Simple question, would there be any noticeable benefit at all from putting two SSD's in Raid 0? Dependent on the above question, are there any cons to using a Raid 0 setup with SSD's?

If specifics matter, the two specific drives in my case would be 240gb Crucial M500's.

 

[Tweakin]

Nope, not for anyone at home or playing games. One thing, access times actually increase in RAID with SSD's, not enough to care about...just something to remember.

 

[Cerb]

Assuming Intel chipset RAID:

Pros:
- Higher sequential speeds
- Higher random speeds, technically (only if you can saturate the drive or the 32 command limit per device)
- Larger total space (usually not an issue, if buying new parts).

Cons:
- Clearing your CMOS may or may not hose the array.
- Any problem with either drive may hose the array.
- Usually more expensive per GB.
- Practical random performance is rarely better than a single larger SSD.

 

[Sunburn74]

I was under the impression higher sequential read speeds may improve level loads in gaming.

 

[mindless1]

As always it depends on your use.

For a multifunction, everyday use PC, you are usually better off using one SSD for OS and the other for apps and games, to split up I/O.

 

[bunnyfubbles]

Assuming Intel chipset RAID:
Cons:
- Clearing your CMOS may or may not hose the array.

are you sure about this? I haven't had an experience to suggest this as true, on the contrary, I've transferred arrays from one Intel chipset to another and it made the transfer just fine...I was under the impression that the array was established on the drives themselves and not within the chipset BIOS...so I'm not sure how clearing the CMOS would/should have any effect...although I will admit I do not specifically recall an instance where I have cleared the CMOS while the RAID was setup, although I've been running at least one RAID0 array on every one of my main rigs ever since s939 nForce4, and have since been partial to sticking with Intel chipsets due the high success rates I've had with moving arrays from one rig to another, even with changes in intel chipsets.

As always it depends on your use.

For a multifunction, everyday use PC, you are usually better off using one SSD for OS and the other for apps and games, to split up I/O.

I was always under the impression that splitting up I/O only truly mattered for HDDs, not SSD, of which RAID0 can and does improve I/O performance...and even though the performance improvement doesn't scale perfectly, I'd love to see the everyday computer use and/or everyday computer user that can leverage any advantage that separate drives might have over a RAID0 setup and end up with tangible results

until convinced otherwise, I can't see how keeping the drives separate would be better outside of reasons of maintenance/organization/safety

 

[mindless1]

^ RAID improves R/W sequentiaql I/O but not as much the IOPS. Usually with an SSD if your game level loads take a long time it's either CPU bound or thousands of small files so IOPS comes into play more than peak R/W performance.

You write that you'd love to see the everyday computer use that leverages advantages as if that's some strange concept. People have been doing this for many years with proven results. While SSD are quite a bit faster than HDD, you're still reducing the I/O each has to do when you split the I/O between more than one, and avoiding RAID latency.

Do your own tests in the specific scenario where you find performance most important. That is the only answer that is best for your particular needs.

 

[bunnyfubbles]

^ RAID improves R/W sequentiaql I/O but not as much the IOPS. Usually with an SSD if your game level loads take a long time it's either CPU bound or thousands of small files so IOPS comes into play more than peak R/W performance.

You write that you'd love to see the everyday computer use that leverages advantages as if that's some strange concept. People have been doing this for many years with proven results. While SSD are quite a bit faster than HDD, you're still reducing the I/O each has to do when you split the I/O between more than one, and avoiding RAID latency.

Do your own tests in the specific scenario where you find performance most important. That is the only answer that is best for your particular needs.

I think you're completely missing my point, I flat out state that having separate HDDs can improve I/O intensive workloads, I'd even go as far to say that its practically necessary; video editing is borderline unbearable with a single HDD or single HDD array, the same is simply not true with SSD (assuming you have enough SSD capacity), as SSD isn't just "quite a bit faster" when it comes to IOPS, its orders of magnitude faster...whether its single SSD, SSD in RAID0, or separate SSD, the average user performing single user tasks is not going to be able to distinguish the difference between any of the aforementioned SSD setups (and thus why I'd like to see the task or user that is able to challenge that, because I certainly haven't seen it), and thus to keep the drives separate for performance reasons simply lacks any merit that I am aware of.

 

[mindless1]

^ Yes an SSD is orders of magnitude faster than HDD, but the question was still which is faster for a particular use when you have two SSDs.

If the user isn't able to distinguish the difference then why are we talking about it? There are lots of areas in computing where the user can't distinguish the difference but then there's those pesky benchmarks that show a number and everyone wants to focus on that.

It seems almost as though you are assuming something rather than having ever tried it. Would you also argue that it doesn't matter if a single SSD alone is 50% faster than a different single SSD, because the slower one is so fast you won't notice the difference? If not, then why not also consider the potential a 2nd SSD /volume has for performance increases?

Your position doesn't make sense to me, it's as though you feel that things are so great we could never want more, even though it obviously will make a performance difference if you have file I/O going to two separate SSD vs one of the same. Again, how much of a difference depends on the specific scenario, but I think we can agree that the OS partition is going to be accessed practically every time you load a game or app, though it is still up to the individual how to split the files on each.

You also mentioned video editing. Do you feel it is faster reading from and writing to the same two drive array concurrently or reading from one SSD and writing to the other? It could go either way depending on the specifics.

 

[beginner99]

From reading all the benches here and on other sites the conclusion is pretty much that RAID 0 SSD are not worth it. In some cases performance can actually be worse, the benefit is limited to sequential transfer at cost of much, much higher risk of data loss.

Don't bother. Use the drives as 2 separate drives or get the 480 GB version.

 

[bunnyfubbles]

^ Yes an SSD is orders of magnitude faster than HDD, but the question was still which is faster for a particular use when you have two SSDs.

If the user isn't able to distinguish the difference then why are we talking about it? There are lots of areas in computing where the user can't distinguish the difference but then there's those pesky benchmarks that show a number and everyone wants to focus on that.

It seems almost as though you are assuming something rather than having ever tried it. Would you also argue that it doesn't matter if a single SSD alone is 50% faster than a different single SSD, because the slower one is so fast you won't notice the difference? If not, then why not also consider the potential a 2nd SSD /volume has for performance increases?

Your position doesn't make sense to me, it's as though you feel that things are so great we could never want more, even though it obviously will make a performance difference if you have file I/O going to two separate SSD vs one of the same. Again, how much of a difference depends on the specific scenario, but I think we can agree that the OS partition is going to be accessed practically every time you load a game or app, though it is still up to the individual how to split the files on each.

You also mentioned video editing. Do you feel it is faster reading from and writing to the same two drive array concurrently or reading from one SSD and writing to the other? It could go either way depending on the specifics.

no, what I'm saying is that keeping SSDs separate instead of putting them into RAID0 is just nowhere near the same as keeping HDDs separate vs. RAID0.

the reason HDDs bog down hardcore with random IOPS is that they're mechanical and the read/write head has to physically move from one place to another on the disc to perform its tasks, the same is not true of SSD, to which you can read and write multiple files simultaneously; the merit behind splitting the drives like you originally suggest just isn't there for SSD like it is for HDD, at least in my experience. Of which I could say the same about you about assuming instead of trying, but please, name the everyday computing task where the separate drives are tangibly faster than in RAID0, because I freely admit to being unaware of it and would love to try it.

 

[bunnyfubbles]

From reading all the benches here and on other sites the conclusion is pretty much that RAID 0 SSD are not worth it. In some cases performance can actually be worse, the benefit is limited to sequential transfer at cost of much, much higher risk of data loss.

Don't bother. Use the drives as 2 separate drives or get the 480 GB version.

from the OP, it sounds like he already has 2 drives

risk of array failure is over-exaggerated in my experience, and considering SSDs are still fairly small, its pretty easy to do complete backups or even partial backups to all but eliminate that risk.

no, I'd say the best reason not to do it if you already have the drives is if your chipset doesn't support TRIM over RAID0, something at least Intel added in a while ago, you just have to make sure you have Z68 chipset or newer and install up to date RST drivers. Not sure about other chipsets.

otherwise I do RAID0 on SSD largely because of the increased capacity thus reducing need to juggle programs, and I then tend to think of any performance increase as a bonus.

 

[Sunburn74]

I think we're all arguing over nothing when this has been tested to death and proven.

http://www.tomshardware.com/reviews/ssd-raid-benchmark,3485-13.html

Long story short, you get better sequential reads and writes. Random reads are the same. Random writes raid-O is much faster. I/Os generally the same at desktop level operations, but scale dramatically for RAID-O once you get past a Q depth of 4. Real world productivity app and OS loading the same.

The lack of TRIM for RAID-0 no longer exists as it was recently discovered that TRIM could indeed be unofficially enabled on chipsets that prior did not support it. The lack on TRIM on those chipsets was something completely arbitrary (and even borderline malicious imo) on intel's part, likely as a mechanism to force people to buy new motherboards for the feature. I think the only real drawback to a RAID-0 setup in this day and age is the higher MTBF something I personally consider trivial after seeing the absolutely abuse my SSDs have been through over the years in terms of random system reboots, electrical outages, etc. My hard drives however are a seperate story (to this day every single conventional hard drive I have ever bought died within 3 years). I recently lost my portable drive after a 2 foot drop whilst in its protective case.

Anecdotally, I will say that my game level loads have been faster since I switched to a RAID-O ssd, but that is anecdotally.

 

[corkyg]

Agree with Sunburn74. If you have adequate capacity SSDs, then, for the average user, RAID0 is gilding the lily. There is also another risk factor other than drive failure. That is, malware or corruption. With RAID0, everything is hosed. With separate SSDs, only one of them is hosed. Speed benefits are, in many cases, only seen in benchmarks.

 

[Batmeat]

RAID 0 now is not worth it for ssd's. Back with 1st and 2nd gen ssd's running them in Raid 0 was noticeably faster because the R/W was nowhere close to what current gen are

 

[Cerb]

are you sure about this?

A few years ago, with an IHC10R, yup. It shouldn't happen, that wasn't something I was trying to troubleshoot, and there were probably additional things going on with what was on the drive, but it saw it and used it until then. On the plus side, it wasn't a RAID 0, but a RAID 1, so trying to recover it wasn't needed.

I was always under the impression that splitting up I/O only truly mattered for HDDs, not SSD, of which RAID0 can and does improve I/O performance

They are the same, in that regard, at least now that NCQ is universally supported.

until convinced otherwise, I can't see how keeping the drives separate would be better outside of reasons of maintenance/organization/safety

Those are the reasons, though until you're over 1TB (SSD) or 4TB (HDD), cost can also be added to the list. Striped RAID of identical drives gives the best overall performance for local drives.