Horrible disk performance on DL120 G7 w/o SmartArray

[LFnet]

Hello,

I have a very "basic" DL120 G7 here (644706-425) which came without a SmartArray controller, i.e. the disks are connected to Intel ICH SATA ports.
I got 2 250GB Entry SATA disks (571230-B21) for it. As usual, the HP firmware on those disks has disabled the drive write cache, which is fine for a buffered SmartArray controller, but leads to extremely poor I/O performance when connected to a SATA controller without dedicated cache memory.

Is there something I have missed? Are there HP SATA disks that have their drive write cache enabled in the firmware and I bought the wrong ones?

Any idea appreciated.
Marco