Lee Revell wrote: > 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? > right. The SATA drive is 250GB. The IDE is 20GB
