Disk access slow down machine

... drives using ext3 and hdparm indicates that I have dma enabled on both of them and that the access itself seems fast enough. /dev/hda: multcount = 16 (on) IO_support = 1 (32-bit) unmaskirq = 1 (on) using_dma = 1 (on) keepsettings = 0 (off) readonly = 0 (off) readahead = 256 (on) geometry = 65535/16/63, sectors = 160086528, start = 0 /dev/hda: Timing cached reads: 794 MB in 2.00 seconds...