PIO mode instead of DMA...

[Mutley]

OK, I'm lazy I'll admit it. I've not spent ages googling for the answer, I thought I'd come here first, given there are so many clever chaps here...

A little while ago I started to notice some odd slow downs on my PC. Its running Windows XP Pro, has 2Gb PC2700 RAM, a 2.5Ghz P4, and two UDMA100 HDDs (one 80Gb and one 200Gb).

The OS and apps are on the 80Gb disk. What I found was that boot-up takes longer, and that many disk read/write operations seem to interfere with running applications. I've even notice that with disk access (I can hear it), the mouse pointer 'hiccups' when you move it at the same time.

I've been thinking there is some process running doing something odd. Of course there are many things running which do disk access, but nothing odd that I can find.

Today I remembered to check the disk access mode through device manager. Both disks are set to PIO mode not DMA, even though they should be DMA! This may explain the problems. I can see no way to set the disks back to DMA. The BIOS is set correctly for the disks as well.

Has any body got any ideas on how this could have happened, whether or not it is in fact significant (I think it is), and most importantly how to fix it??

Thanks!

Mut.

[Mutley]

I decided to have a quick google around anyway, and to my great surprise stumbled across a fix straight away.

It seems that Windows XP (for safety reasons...hmm), will default to PIO mode on ATA HDDs and CD drives that it has problems talking to in DMA mode. Not that it tells you of course. This could be caused by many things.

Anyway, here is one solution:

http://winhlp.com/WxDMA.htm

I downloaded and ran the VBscript programme, which reset the DMA status of all my drives. After reboot, all drives are now operating correctly in DMA mode (UDMA mode 5 in fact). Things are palpably faster....

Hope this helps someone!

[max99]

The usual method for fixing this problem is to simply delete the IDE channel (either Primary or Secondary, depending on which one has reverted to PIO) from Device Manager and rebooting. The IDE channel will be automatically reinstalled and set back to the correct DMA setting.

[dave87]

Wish I'd seen this thread earlier, as I would have emailed you the same script - used it on my laptop after a scratched CD caused it to revert to PIO mode...

[Mutley]

Thanks for your replies guys. I'll remember the channel deleting approach for next time...!

[slacky1230]

can some body tell me how to find if my drives are running pio or dma as i to heard my hard driving going and also operations like moving files interfear with things

[MadduckUK]

that was a bit drunk man, but control panel -> system -> hardware -> device manager -> IDE ATA/ATAPI controllers then looking at the relevant channels (if you don't know look at all of them!) to see what mode its running in.

[slacky1230]

1 seems to be running in mode 2 and there other in mode 6 theres a little tick box that says enable dma and there both ticked

[MadduckUK]

i have a mode 4 and a mode 6, the mode 4 being my DVD-RW and the mode 6 a SATA HDD.