SSD Raid-0 Advice

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A few weeks ago I posted asking for opinions about OCZ's PCI-E SSD Raid-0 card and most of the responses were against it. So I've decided not to get it and just get an additional G2 80GB (see system specs in sig) and with Intel dropping the price below $200 it makes more sense, plus I'll have the option to stick it in a laptop later if I choose to.

So to my understanding with 2 SSD's in raid-0 I will be close to or hitting the bottleneck of my SATAII controller and to get the full benefit I will need to use a PCI-E raid card. If my understanding is correct, I'd like some advice on raid card options. Feel free to tell me if my train of thought is wrong 😀

Thanks!

 

[sub.mesa]

You want to buy an add-on RAID controller? If you have Intel southbridge (ICHxR) then you can use Intel's RAID drivers, which are quite good if you want performance. Buying a separate RAID controller just for RAID0-ing SSDs is a complete waste of money, in my opinion. Besides the Intel onboard RAID option should be faster, especially when you enable the write caching option in the Intel RAID drivers.

You will lose access to TRIM, however, when putting SSDs in RAID under Windows OS. You may want to read about overprovisioning and how it helps to fight performance degradation over time. Essentially you can sacrifice some storage space to make the SSDs not degrade as quickly in performance.

 

[Burner27]

I had my 2 x 80GB Intel SSDs in a RAID 0 array for my OS. According to AS-SSD, I was get ~531MB/s sequential reads and 160MB/s sequential writes. I overprovisioned the free space by about 20% which gave me an array of ~120GB for my OS and apps.

Things were nice and snappy, although not much snappier than just running one 80GB by itself. After a month, I re-benchmarked again and the reads dropped to ~490MB/s and the writes dropped to ~150MB/s. I didn't notice it however.

What I did notice was this: unless you are going to use most of the space you have allocated to the array for whatever OS/Apps you normally use, a RAID 0 array is a waste. The slight performance boost wasn't very noticable either.

I switched back to using each drive separately and have better utilized them. I also gain back TRIM (Although that was not why i switched back)

 

[corkyg]

. . . What I did notice was this: unless you are going to use most of the space you have allocated to the array for whatever OS/Apps you normally use, a RAID 0 array is a waste. The slight performance boost wasn't very noticable either.

I switched back to using each drive separately and have better utilized them. I also gain back TRIM (Although that was not why i switched back)

Good choice! RAID 0 with SSDs is gilding the lily and creating an unnecessary higher risk of data loss.

 

[Collider]

You want to buy an add-on RAID controller? If you have Intel southbridge (ICHxR) then you can use Intel's RAID drivers, which are quite good if you want performance. Buying a separate RAID controller just for RAID0-ing SSDs is a complete waste of money, in my opinion. Besides the Intel onboard RAID option should be faster, especially when you enable the write caching option in the Intel RAID drivers.

But wouldn't I be limited by the SATAII controller? for some reason I was under impression that the bottleneck would begin with speeds exceeding ~300Mb

Also, I'm already running my WD Blacks in raid using the mobo controller, would I incur a performance hit by setting up a 2nd raid on the same controller?

 

[HendrixFan]

But wouldn't I be limited by the SATAII controller? for some reason I was under impression that the bottleneck would begin with speeds exceeding ~300Mb

Also, I'm already running my WD Blacks in raid using the mobo controller, would I incur a performance hit by setting up a 2nd raid on the same controller?

The ICH0R maxes out a RAID array at around 650 MB/s. With some drives you can hit that peak with just two drives, others will take three or four. To go faster you will need a dedicated and expensive RAID card, a cheap one will not get you better results than the ICH0R.

The only performance hit you would get with separate arrays would be if you were moving data on both at the same time.

 

[Collider]

The ICH0R maxes out a RAID array at around 650 MB/s. With some drives you can hit that peak with just two drives, others will take three or four. To go faster you will need a dedicated and expensive RAID card, a cheap one will not get you better results than the ICH0R.

The only performance hit you would get with separate arrays would be if you were moving data on both at the same time.

That clears it up - Thanks!