Using SSDs in RAID0

[EarlGrey]

There seems to be very little talk of using SSDs in RAID0.

Surely you can buy two 120GB drives, put them in RAID0 and see a performance increase over the equivalent branded 240GB drive...

But something tells me I have missed something. Are the controllers just not capable? Is reliability that bad?

I'm tempted to get two 120GB M4s. Comments?

[GoNz0]

you can but trim will not work.

if its an intel chipset trim will be along soon for RAID0

http://www.station-drivers.com/telec.../sata/11.5.htm

[kalniel]

There seems to be very little talk of using SSDs in RAID0.

Surely you can buy two 120GB drives, put them in RAID0 and see a performance increase over the equivalent branded 240GB drive...

But something tells me I have missed something. Are the controllers just not capable? Is reliability that bad?

I'm tempted to get two 120GB M4s. Comments?

SSDs in RAID 0 are top performers, there's no question about that. The thing is you won't notice the difference, because a 256mb drive is already blindingly quick (SSDs use the equivalent of internal RAID anyway, so as you increase the capacity you generally increase the speed as well, even within a single drive). So while you might benchmark at higher scores, the real world difference will be quite small or unnoticeable. On the minus side if one disk gives an error then your whole lot goes down and the data is corrupted, so you're doubling your risk (two chances of having bought a drive with reliability issues vs one), and at the moment you can't TRIM (way of fully clearing data on delete, which prevents drives from gumming up with uncleared data).

On the first hand again, it might be economically better to buy two smaller capacity disks than one big one.

[EarlGrey]

Thanks for the two great replies
I think one m4 now, and perhaps (with the possibly impending intel support for Trim) a second when Ivybridge tempts me out of all of my money...

[Luckygiant]

you can but trim will not work.
if its an intel chipset trim will be along soon for RAID0
]

Unless you're doing some pretty hardcore work you're never going to notice a difference.
...You don't want to be losing TRIM.

[mikerr]

The huge advantage of SSDs over HDDs is access time, RAID0 won't improve that at all.

[billg]

but is this also true for editing large video files (>2GB) and does the software for this make a difference between a 240 GB SSD and 2x 120 SSD in RAID0 ?

[billg]

Unless you're doing some pretty hardcore work you're never going to notice a difference.
...You don't want to be losing TRIM.

Any idea how soon?

[chates]

I've been thinking along similar lines but the main reason I haven't so far (I wasn't aware you lose TRIM so thanks for that! ) is that two smaller drives are generally more expensive than the equivalent larger drives. I was thinking of 2 60's to run games on with my existing vertex 2 being my OS drive.

Looks like I'll be holding off for a while until I can afford a larger drive then!

[chrestomanci]

For a server at work we brought six 512 Mb Crucial M4 SSD, and put them into a RAID-5 array.

I am not looking after that server, but the guy who is says it is fairly speedy.

[EarlGrey]

For a server at work we brought six 512 Mb Crucial M4 SSD, and put them into a RAID-5 array.

I am not looking after that server, but the guy who is says it is fairly speedy.

fairly speedy

[Agent]

The TRIM issue isn't such a big deal - Sandforce, Kingstons, Intel, Toshiba, Samsung and so on, all have their own internal garbage collection. Sandforce for example pretty much ignore TRIM and do what they feel is best, although there is no way I'd ever recomend a Sandforce.

There is a thread on the Crucial forums where people try to slow the M4 down by using it without TRIM, and it just doesn't happen. It escapes me right now though.

It depends on the drive and firmware, don't get me wrong, but most modern drives have good GC now do you don't have to worry about them in RAID.

That to one side though - unless you need some insane throughput from the drives, RAID won't give you a real world speed increase for most things. Their 'speed' comes from the random access time, not the sequencial speeds.