is there any reason that enabling DMA on a hard drive would affect avisynth good or bad? xnakx

It should definitely affect it for the good, especially if you are working with a large filesize source, like uncompressed or huffyuv video. Probably wouldn't help so much with mpeg sources, but it shouldn't ever hurt to have dma enabled for your drives.

You shouldn't ever be running HD's in PIO mode because access to PIO mode devices costs you a lot of cpu power (about 50-100%...) and in addition to that, the transfer rate will be limited to about 16MB/s in PIO mode 4. I guess everyone here using avisynth has DMA enabled for his IDE HD's, so you can be pretty sure there are no problems with it.

well when i enable DMA for the DVD drive rip speeds are increased substantially, But when i enable it for the hard drive(IBM DeskStar 40g) I have read errors and execption errors with Avisynth. Disable it on the HD and things are all well agian. I guess i should take a look at the other components (RAM, MB) thanks for the replies

ok thanks for all the help