DELL PERC 4/SC low performance

I doing some performance test with openbsd 3.8 in a PowerEdge 830 with perc 4/sc board. 'dd if=/dev/sd0c of=/home/test1 count=4000 bs=256k' gives a transfer rate of 6MByte por second. This is really slow... other operating systems get a throughput of 45 mbyte por second. Setting Write-policy to

Re: Dell Perc 4/SC low performance - SOLVED!

Solved the problem. Marco Peereboom suggested to check writeback cache and I obviosly missed that. Thank you. Regards, Mitja Mitja wrote: Hi, I am trying to figure out why the performance of PERC 4/SC RAID controller is so poor. I've searched the archives but nothing usefull came up.

Dell Perc 4/SC low performance

Hi, I am trying to figure out why the performance of PERC 4/SC RAID controller is so poor. I've searched the archives but nothing usefull came up. I'm running OpenBSD 3.8-release on a Dell PowerEdge 1800 server, RAID 5. # time (dd if=/dev/zero of=x bs=1m count=100; sync; sync) 100+0 records in