Сабж хотя DMA работает
# uname -r 2.6.22-3-686
Debian unstable
# lspci | grep IDE 00:1f.1 IDE interface: Intel Corporation 82801DB (ICH4) IDE Controller (rev 02)
# hdparm /dev/hda
/dev/hda: multcount = 0 (off) IO_support = 0 (default 16-bit) unmaskirq = 0 (off) using_dma = 1 (on) keepsettings = 0 (off) readonly = 0 (off) readahead = 256 (on) geometry = 65535/16/63, sectors = 156301488, start = 0