2009/8/11 Ian Murray <murrayie at yahoo.co.uk>: > In my haste for help, I stupidly hit reply and changed the subject which I > thought was enough for a new message, not giving much thought for the > threading, etc. So apologies for the hijack, although I would think it > fairly obvious that it wasn't deliberate or obvious to me... or a big deal > really. My mail doesn't thread. > > Some further info for those actually interested in helping, I forgot that > the HD in question had an Ubuntu 8.10 install on it, so I fired that up and > hdparm -t produced 56MB/Sec. So the issue is either kernel or config. Check if ultradma and unmasq interrupts flags are set(both under ubuntu and centos): hdparm -u -d /dev/hda