nvidia RAID5 is somewhat slow - tips for improvement?

[kleptophobiac]

Specs:

5x 500GB WD SATAII 16MB
1x 150GB WD Raptor
MSI K9N SLI Platinum (nforce 570)
Athlon X2 4600+
2GB Corsair XMS DDR2 800 Pro
Truepower 2.0 550w

Anyway, the five drives are in a RAID5 array... and I can only move about 12MB/s to the array. That seems rather slow. I've got a linux software RAID5 array that can move around 30MB/s with a much less powerful CPU. The raptor is zippity quick... so I don't think it's a problem with drivers. Is the nvidia controller just that bad with parity calculations?

 

[defakto]

It's an onboard controller, all calculations are done in software which could be a small part of the overall problem.

 

[unhappy_mage]

Are there settings for "write-through" versus "write-back" cache? What options are available?

The other "tip for improvement" would be "don't use nvidia rad 5"

 

[drizzt81]

Anyway, the five drives are in a RAID5 array... and I can only move about 12MB/s to the array. That seems rather slow. I've got a linux software RAID5 array that can move around 30MB/s with a much less powerful CPU. The raptor is zippity quick... so I don't think it's a problem with drivers. Is the nvidia controller just that bad with parity calculations?

well, if nVidia's software raid drivers stink, it would not affect your raptors performance, but only that of the RAID array.

 

[kleptophobiac]

Well, the CPU certainly isn't maxed... so doing it all in software doesn't seem to be the bottleneck.

There are no cache options whatsoever.