Does using DMA make your computer Slower?

[kyrios]

Does using DMA (direct memory access ) make your computer slower. In my case it does. On my 3.2 Ghz P4 HT cpu with 1GB of ram it takes,(with dma on) twice as long to rip a full length dvd to the hard drive than it does my older 2.53GHz P4 cpu wih 512MB ram.
I'm wondering why it's slower, because I thought DMA would make it faster. The DVD drive on my new computer is also faster and a faster harddrive( serial compared to IDE) as well. So I was wondering if I should turn DMA off or something, because it doesn't make sense at all.

[Nokia]

Not all drives support DMA. If you enable it and it is unsupported - obviously this will lead to problems!

If your system seems to be going faster when it is disabled, I would say this is a sure sign that something in your setup doesn't support it.

Check your manual first - or post the make of your DVD RW / HDD!

[kyrios]

Do you know how I can turn it back off with Windows XP machine?

[Nokia]

http://www.real-knowledge.com/dma.htm

You may still be able to leave it enabled for either the HDD or DVD RW - depending if they support it.

The site I linked to will help you!

[kyrios]

There is only one option for the transfer mode other than DMA and it's "PIO only", should I select that option to turn it off?

[rcgreen]

http://www.microsoft.com/whdc/device...e/IDE-DMA.mspx

PIO is the fallback mode for when things go wrong, and it is slower.