Choosing 2 x SSD's for RAID

[cytg111]

And I am torn between the 830 and m4.
I have the M4 in an e450 eeepc nettop and it is smooth as silk, reading

http://www.youtube.com/watch?feature=player_embedded&v=ZT3U4LP1jxE

The M4 and 830 is pretty close competitors, nothing you would notice outside of a bench, so i am learning towards the devil i know, 2 x 256gb M4's. Also, the GC of the M4 will do good in a raid setup, dont know how the 830 fares there.

Ill pull the trigger on this in ~24 hours, please feel free to intervene🙂

 

[kbp]

Both good drives. I guess my decision would fall on the price.

 

[Coup27]

I would go with the 830s personally, but theres not much between them.

 

[Shagga]

So does putting two SSD's in RAID 0 for instance improve performance significantly?

 

[moriz]

So does putting two SSD's in RAID 0 for instance improve performance significantly?

It will double sequential and high queue depth 4K performance. Randoms theoretically should not improve, since you can't set a stripe size low enough. but exdeath posted a screen shot that proved otherwise. No idea how he did it, and he didn't elaborate.

Until he does, I'd still say that you shouldn't bother unless you are running server level loads on it. It is a good way to increase the size if your drive though.

 

[cytg111]

It will double sequential and high queue depth 4K performance. Randoms theoretically should not improve, since you can't set a stripe size low enough. but exdeath posted a screen shot that proved otherwise. No idea how he did it, and he didn't elaborate.

Until he does, I'd still say that you shouldn't bother unless you are running server level loads on it. It is a good way to increase the size if your drive though.

Agreed, and i've moved onto the 512gb M4, dumping the raid hazzle.

 

[Coup27]

Personally SSDs are so fast, if I needed 512GB, I'd rather have one drive. Far less to go wrong when things go a bit funky.

 

[taltamir]

I would wait until intel's TRIM compatible RAID0 driver is actually released before buying the drives

 

[God Mode]

I had different raid 0 ssd for a while but I don't bother anymore.

I experienced severe degradation after a few months of average usage where a single drive was faster than two at raid 0.

 

[taltamir]

I had different raid 0 ssd for a while but I don't bother anymore.

I experienced severe degradation after a few months of average usage where a single drive was faster than two at raid 0.

Yep, that is why TRIM is so important. If you are gonna RAID0 SSDs without TRIM you should use a minimum of 3 just to overcome the performance degradation.

 

[moriz]

odd. i noticed zero degradation of performance over six months of fairly standard use. the drives were intel 320 120GB.

 

[taltamir]

odd. i noticed zero degradation of performance over six months of fairly standard use. the drives were intel 320 120GB.

Degradation is a misleading name for it.
Performance drops after the drives have been written to once (that is, an amount equal to their space, happens within days) and then slightly fluctuates about the "used state". It doesn't constantly go down.

Also many makes ship drives in the used state intentionally to avoid customers freakout. Not sure if intel does though. With a pair of intel drives thought you could easily not notice it.

You could test it via benchmarking. Benchmark them as is, then secure erase each drive individually and recheck with cleared drives.
Or more easily, benchmark it as is now and compare it to reference speeds / speeds single drive systems are getting

EDIT: Oh yea, there is also GC.

 

[cytg111]

ty : 512G m4 it is 🙂

 

[moriz]

Degradation is a misleading name for it.
Performance drops after the drives have been written to once (that is, an amount equal to their space, happens within days) and then slightly fluctuates about the "used state". It doesn't constantly go down.

Also many makes ship drives in the used state intentionally to avoid customers freakout. Not sure if intel does though. With a pair of intel drives thought you could easily not notice it.

You could test it via benchmarking. Benchmark them as is, then secure erase each drive individually and recheck with cleared drives.
Or more easily, benchmark it as is now and compare it to reference speeds / speeds single drive systems are getting

EDIT: Oh yea, there is also GC.

performance was around 460/260 MB/s sequential throughout the entire six months, which is just under double the drives' normal performance.

the 320 series does have probably the best GC out of all modern SSDs, so maybe that's the deciding factor.

 

[taltamir]

the 320 series does have probably the best GC out of all modern SSDs, so maybe that's the deciding factor.

Yes. Combined with how often you write to it (the more you write, the more work there is for GC, write once and read often stuff like the OS doesn't pose an issue).

So if you do go with SSD RAID make sure its a model with outstanding GC...
Or get one awesomely fast single SSD like the 520 and wait for intel to finally release the TRIM on RAID0