UDMA Hard Disk and DMA Access
Posted on 2000-04-06
I recently put togehter a system with an Asus K7M with an Athlon 700Mhz CPU & 128Mb PC100 SDRAM. The BIOS has UDMA support and I moved an "old" Maxtor DiamondMax Plus 5120 series UDMA66 HD to use with it. Though the system "seems" quick enough I was disappointed with the throughput and felt I should be getting quicker disk access. While checking around I noticed that there is NO DMA button in the device manager/ disk drives/ maxtor/ properties/ settings tab of the Maxtor drive. It is my understanding that if the drive is using DMA access (which it should) there should be a DMA button checked. I'm using Win 98SE, the latest BIOS v.1008 (downloaded and flashed) and the latest IDE drivers (downloaded). The list of used DMA channels does not show that the HD is accessing any channel. Is it possible for the BIOS to have access to the HD in UDMA mode without a dedicated DMA channel? Only DMA2 (FD) and DMA4 (DMA access controller) show as being used at all.