On Sat, 2006-02-18 at 13:55 -0800, Brad Fuller wrote: > Lee Revell wrote: > > > > This helps a lot: > > > > echo 64 > /sys/block/hdc/queue/max_sectors_kb > > > > (replace hdc with your drive, repeat for all of them) > > > > Try that before you resort to patching the kernel. > > > > IIRC PD is not the best designed RT app (GUI stuff can delay the RT > > threads), but this might have improved lately. > > > What is given up by setting this to 64? Presumably, a little bit of disk performance. Low latency always involves giving up some performance, because it's a matter of doing some kind of work in smaller chunks. I have not measured it. > I have a sata set at 1024 and an > IDE at 128. Certainly they were set at these settings for a reason (I > hope a good reason) > Heh, that's a funny story - it's actually the farthest thing from a good reason I can imagine. The maximum IO size is determined by whether 48-bit addressing is in use which is determined by - wait for it - the size of the drive! The sata drive is bigger than the IDE right? Lee
