some general questions..

[Raudi]

what kind of controller do you use?
we had similar problems with 3ware products (eg 9550), on high IO situation the r/w performance dropped down to constant 8MB/s for minutes, then rising again for some time, again dropping...

I use a 3ware 9550SXU-16ML... This sounds not good, but i hope the issue is fixed. Uses here someone a 3ware too and can tell his experience?

Regards
Stefan

[Robotbeat]

We used a 3ware 95xx series card (first half of 2007), and we had horrible performance. We also switched to an Areca controller.

[netsyphon]

we use 9650 controllers and have no problems.

if i could go back however i would have bought Arcea.