SATA 3.0 Problem (speed too low)

[Cephyr13]

I RAIDed two western digital 7200 rpm SATA drives that average 82MB per second transfer rate each. On a striped RAID setup, I should be getting 164MB per second, theoretically. Realistically, I expected at least 155MB per second transfer rate. I'm getting 110MB per second transfer rate. The HD jumper settings are set to 3.0GB/s through put, not 1.5GB/s.

On another computer, I had 2 10,000 rpm SATAs that only do 101MB/s tranfer rate, and they should do 140MB/s. How can I get the transfer rates where they're supposed to be on these systems?

 

[Lord AnthraX]

it might be your onboard raid controller possibly.

 

[Cephyr13]

It happens on my DFI motherboard as well as my Asus motherboard, both with onboard RAID controllers. Therefore, I would tend to think that it is not the onboard RAID controller.

 

[Nitestick]

RAID won't get you 200% the performance of a single drive. i think the integrated controllers you are talking about are part software based so that's probably where the inneficiency is.

 

[Cephyr13]

I just used SiSoftware Sandra to run a benchmark and I found that I'm actually getting 133MB/s transfer rate. The last test I did was incorrect for some reason. Don't know why. So, the drives are a little bit closer to the speed they're supposed to run at.

But, since their theoretical speed is supposed to be 164MB/s, that means you should get around 155MB/s with a bit of loss, which is typical. So, I am still a little behind...but not enough to discourage me now.

I'm using the integrated onboard RAID controllers, and for some reason it calls it a SCSI setup instead of a SATA setup. Haven't figured that one out. But, I'm okay with 133MB/s throughput. I'll have to just add a third drive to the RAID if I want 200MB/s. No big deal.

I'm not sure if it's a software problem or not, but that could be the reason for the loss of transfer rate. Thanks for the help.

 

[CrazeD]

SATA is SCSI.

 

[Cephyr13]

What makes you think SATA is SCSI? SATA is similar to SCSI in the way it works, sure. But why would you say SATA is SCSI?

 

[Nitestick]

SATA is not SCSI. SAS (a form of SCSI) is very similar to SATA though.