Why are my cd drives showing up as Multiword DMA Type 2 instead of udma?

[tydas]

Im' using winxp

 

[Jeff7]

What exactly is UDMA? My DVD drive is ID'd by BIOS as being in UDMA Mode 0. Windows says DMA Mode 3. Is it just Ultra DMA? I thought that was kind of a buzzword.
Either way, as long as it's using DMA, there shouldn't be performance issues; I don't think CD drives come anywhere close to 33MB/sec anyway.

 

[stevewm]

Multi-Word DMA 2 is PIO Mode 4 but with DMA data transfers. It will provide up to 16.6MB/sec of bandwidth, CD=ROMs generally average around 4MB/sec, getting up to 7MB/sec on the outter edges of the disc.

ONly modern CD-ROMs or CD-RW's will run in UDMA 33 Mode.

Nonetheless you'll be just fine fine MWDMA-2. CPU usage in this mode is about the same as UDMA 33.