Gerard Beekmans wrote: > Enable it in your BIOS for starters. Then your kernel needs to have DMA > enabled as well. I assume yours does, but in case it doesn't, compile a > new kernel. DMA is under "ATA/IDE/MFM/RLL support" --> "IDE, ATA and > ATAPI Block devices" --> "Generic PCI bus-master DMA support" option, as > well as "Use PCI DMA by default when available" option.
you may also need to enable support for the chipset your mainboard uses to get the highest level of UDMA. I've had boards in the past that would only do UDMA-2 (ATA/33) if the right chipset wasn't enabled. For a while when I first had my nForce board, the 2.4x kernel didn't support it yet so I was limited to UDMA-2 but once the support got added to the kernel I was able to get the full UDMA-5 (ATA/100). Note, in order to get UDMA-5, you need to use an 80-pin IDE cable. Of course you only need an 80-pin cable if your drive (be it cd/dvd or an ide hard drive) supports UDMA-4 (ATA/66) or greater. this page has good info, including pictures of 40 pin and 80 pin cables. http://www.pcguide.com/ref/hdd/if/ide/conf_Performance.htm Dave
