[QUOTE=KevN2008;2154285]I could no longer retreive files off of a CD/DVD while in Windows. It would just hang up as the CD spins, sometimes the folder would open eventually but very very slow and then it would hang again when trying to access a file.
Finally I went into BIOS and changed the PIO/DMA setting for the original CD drive from auto to PIO3 and DMA3. Im not sure really why but it worked. CD’s worked in that drive, but still not the other. So I changed settings in the other one to PIO2 and DMA2 (do they conflict if they’re the same #'s??) and that fixed that one too.
Programmed IO (PIO) requires the CPU to stop what it’s doing, retrieve data from the drive, and then write it to RAM.
Direct Memory Access requires the CPU to disconnect from the RAM bus (but not stop what it’s doing) while the Drive transfers a block of Data directly into memory at high speed.
The original DMA was about 3 times faster transfers than PIO … since then, they’ve developed “Multi-Word DMA”, UDMA1, UDMA2, UDMA3, UDMA4, UDMA5, UDMA6 which (or course) gets faster in every revision.
Current standard for IDE optical drives is PIO4 & UDMA4 (depending on how recent your drive is it may only be UDMA2, or UDMA3).
Typically, PIO mode pauses your computer for 1/2 a second for every drive access. It works, it’s just incredibly slow.
It’s your call on the settings you want.