Dismal performance with X25-M 80GB drives on a 3Ware 9690SA controller

Well, my SSDs arrived yesterday, and I got them all mounted up

http://www.linustechtips.com/wp-cont..._1478-1600.jpg

http://www.linustechtips.com/wp-cont..._0241-1600.jpg

I really wanted to benchmark the heck out of them before I actually load on my OS, and once I enabled write back cache I'm getting numbers on the ICH10R controller that are about what I expect (maxes out at 630MB/s read with 3 drives, and 4 doesn't help, then maxes out around 300MB/s write with 4 drives).

The 3Ware 9690SA-4I on the other hand is giving me absolutely horrible numbers. With two drives I'm getting very inconsistent reads (it wavers up and down constantly from about 200MB/s to 150MB/s).

Is there a setting for the 3Ware card that I should be enabling that is similar to write back cache? Here is the configuration of the drives in TW_CLI

http://www.linustechtips.com/wp-cont...i-settings.jpg

Here's performance on the 3Ware card. 2 drives, 64k stripe size:http://www.linustechtips.com/wp-cont...read-3ware.png

Here's performance with the same settings on the ICH10R: http://www.linustechtips.com/wp-cont...he-enabled.png

do you have a different raid card to test with? I think on the areca 1231 or something similar you might get 700 to 800MB/s reads with all 4 drives enabled. Companies need to build better raid cards because these SSD's are pushing new limits in terms of performance

The 3Ware card might have older IOP? IOP is what limits the sequential read/write mostly today.
The ICHxR might be limited by PCI-e lanes, and the speed max of ~600-700MB/s is a good indicator of this. (i.e. you can get more)
What you would use such speed is beyong me really, since you won't be copying large files to SSDs often. It's their random read/write that you benefit from.

Quote:

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Originally Posted by alfaunits

The 3Ware card might have older IOP?

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3Ware don't even use Intel IOP processors, they're using RISC and that's what makes them suck@performance.
I have to admit though, that they offer nice features and stable operation.

Linus: if you wish to see your theoritical 800+ Mb/sec read speed, you need to invest to a RAID card with a mid-high end Intel IO processor, imho at least IOP333/332 (800MHz)

If you want to be as future proof as possible, then you need to get one of the dual core IOP348 ones :)

I don't have a different RAID card to test with, but it doesn't make sense to me that the 3ware RAID card would be limited to 200MB/s in RAID0. What's worse is the inconsistency in the performance. SSDs shouldn't waver up and down that way, it should be near constant like it is in the ICH10R test.

What makes you guys say that I would need a RAID card with an Intel IO processor? It's not like a 3ware card *should* be limited in any way to 200MB/s. Here's a review with a 4 drive magnetic RAID 0 array getting over 300MB/s... http://www.pcpro.co.uk/reviews/17571...-9690sa8i.html

write back not enabled @ 9690

should be @ bios options/when the array is created

write back cache disabled = raid not fully functioning - basically the performance of 1x drive actually less just the GBs of all drives
write back cache enabled = fully functioning raid

optimal raid0: read/write cache enabled

i must say, those SSDs *look* sexy! :D

can try the web manager to get to this page

Well, here's what I have set in the BIOS, so it APPEARS to me that write caching is enabled... Maybe it's pebcak though...

http://www.linustechtips.com/wp-cont...2/img_0249.jpg

Spent some time on the phone with 3ware tech support this morning and learned a couple of new things.

1) 3ware openly admits their controllers don't work properly with SSDs. Last time (pre sales) I talked to their tech support they said "testing isn't completed", but they didn't flat out tell me it doesn't work, so I told him I was going to give it a shot (at that point he could have told me...)

2) HD Tune evidently is incompatible with 3ware cards. I guess that would explain the crummy results I'm getting in this benchmark with both the X25-M and my Samsung F1 (weird results show a wavy line instead of a normal HD curve).

3) IO meter will not return decent results unless I use a command queue depth of at least 10. This one makes no sense to me. We're talking RAID-0. This is not complicated hardware processing. You take the data, you put it on the drive, you take it back off the drive. Very simple.

Even if these things are common knowledge in the community, I didn't know, and individually they suck, but all together they make 3ware cards NOT a good option for those looking to build SSD and/or RAID-0 arrays. :(

Looks like I need a new card.

The problem is 3ware sucks. I am sorry but that is all it really comes down to. I have about 80 9650se's at work and 5 or so 9690SA's. The 9690SA's are a bit better than the 9650se's but i am seeing about 200 MB/sec max on the 9690's as well and that is even with a 24 drives raid0 with 1.5TB seagate drives. I am pretty sure these controllers simply can't push more than 200MB/sec. If you want faster speeds you will want the ARC-1230ML or higher. That card caps out at around 830 reads and 700 writes (non parity raid) and 830 MB/sec reads and 650 MB/sec write (raid5) and 600Mb/sec write (raid6).

The ARC-1230ML is a bit expensive and the next best performer with SSD's I believe is an ARC-1222 (more in the price range of a 9690SA). which will cap out at around 550-600 MB/sec reads and 400 MB/sec writes.

EDIT: If you don't need 8 ports I think the ARC-1212 is the same specs as the 1222 (not positive on that) and only has 4 ports. I have only used the ARC-1222 so I can't comment about differences in performance.

I think at this point I'm just going to stick with onboard unless there's some compelling reason not to.

ICH10R will do 600MB/s reads and 300MB/s writes with these drives, and this upgrade has already dramatically exceeded my original budget :(

Good to know about your similar experience with the cards though. I've seen a couple things around the web during my research suggesting that 3ware cards do not use their onboard RAM for anything other than RAID-5/6, so that would be consistent with our experiences....

I'm going to parrot what I usually suggest, a ebay dell perc 5i would be a good controller to give a whirl and is 50-75$ and is probably better

Actually I almost definitely the perc will get lower raid0 performance than his intel onboard raid did (going from the numbers he gave). The only reason I would suggest hardware raid when he is able to get those numbers is if he was running parity raid (not raid0).

Yeah I don't think I have any choice other than to use onboard RAID or save up some more money and get a nice Areca....