PIO, DMA, 32bit transfer questions

radish 2005-02-13 13:14:21 UTC #1

I am trying to improve the performance of my Plextor Drive. One thing i find really annoying is that the drive switches to PIO if i get errors. can i force it to stay on DMA2?

in the bios what does 32 bit transfer mode do? and also what are Fast Programmed I/O Modes? what should i set these to?

what i find really annoying is the descriptions the BIOS gives.

32 bit transfer mode: check this to enable transfers in 32 bit. DUH

Razor1982 2005-02-13 13:35:49 UTC #2

32 bit transfer mode: check this to enable transfers in 32 bit.

yes, that's the answer... if you disable this feature the transfer will only be 16 bit, which will slow down ide-performance and higher the cpu usage...

what do you mean with:

One thing i find really annoying is that the drive switches to PIO if i get errors.
???
normally, a drive may not just switch to PIO mode...

radish 2005-02-13 15:25:56 UTC #3

This PIO thing seems to be quite a random and rare thing but when i am having performance problems with my drive i do a hardware check which reveals it is running in PIO. I then assumed this was due to transfer errors since i remeber reading up how the IDE controller will decrease the transfer mode until all errors are stopped

Razor1982 2005-02-13 22:22:25 UTC #4

i don't know exaclty where, but there is a reg.-patch around in these forums which forces win 2k / xp to use the dma mode instead of pio... this might be a software solution..

but maybe there is something else? is your ide-cable ok? try to change it if you're not sure...

G11 2005-02-14 01:19:58 UTC #5

Actually it's not the drive that's doing that but the operating system. When the drive reports errors a certain number of times, Windows XP will set the DMA option to PIO mode 4. This thread has some good information on Windows XP and the DMA settings.

VeryBadBoy 2005-02-14 01:44:36 UTC #6

Try a better 80pin EIDE cable - XP is probably detecting some errors with your current cable.