I have recently built a PC with an Asus AV8-VM motherboard running Windows XP Service Pack 2. I have noticed that when I start the PC the Bios is identifying the hardrive as being UDMA Mode 3 but I know that the drive is UDMA 5. However, when I am in Windows the drive is correctly stated as UDMA Mode 5 in Device Manager. I have looked at the Bios settings for the hardrive and they are all set at Auto. I can manually set the DMA Mode for the drive to UDMA Mode 5 but I am wondering why the Bios on the Auto setting is only stating UDMA Mode 3. Is it alright to manually select UDMA Mode 5 for the drive or can it corrupt data or cause any other damage to the drive. Any advice on this matter greatly appreciated.
I gather that Windows (from XP onwards) can override certain BIOS settings, so this may be what is happening.
I remember having a Western Digital drive that the BIOS showed as a lower UDMA level than the drive ostensibly supported. WD provided a utility which enabled one to change the UDMA level of the drive - I thought this was something actually set on the drive, as I couldn't see anything in the BIOS to change. Anyhow, the utility worked.
But as /\0/\ says, probably not worth messing with.
Thanks for your replies. I use Norton Ghost to image my Windows XP Partition outside of Windows. The image is restored considerably quicker if I manually select UDMA Mode 5 from the Bios settings than if I leave the Bios on Auto setting (The Bios detects the drive as UDMA Mode 3). Is it OK to manually select the UDMA mode? I am puzzled why the Bios is stating a lower UDMA mode.