05/01/2004

DMA Trials

DMA, for the newbies in the area, refers to Direct Memory Access - allowing devices on IDE channels to communicate directly to RAM, rather than going through your processor. Click here for a more complete definition, if you want the technical details. As you might imagine, this was a major breakthrough, and resulted in a fairly large performance boost. Now, with hard drives commonly getting real read speeds of 50MB per second, it is more important than ever. If you have to pass every request through your processor, guess what? You are seriously bottlenecking your system. And you want to know something else? Microsoft Windows XP, though it is the best OS ever, will sometimes put you back in PIO (program input/output) mode, which is drastically slower and uses major resources, and it doesn't even bother to inform you when it does. To check, open the Device Manager to check what mode your drives are using. If you have noticed strange slowdowns, check for spyware, then this. Take it from me - you will notice if it happens to any device you use more than once a year. Microsoft has acknowledged this is a problem, and offer a patch to fix it. However, you have to contact "Microsoft Support Services", because they have not made a download available. There is some good news, however. Windows XP Service Pack 2 should contain the fix, hopefully making this blurb obsolete. I am not holding my breath - let's just leave it at that. If you have to fight this beast, I wish you luck. Just be careful when you go searching for help - a lot of people recommend registry hacks that you shouldn't have to do anyway, and half the time (or more) the instructions don't work. I went through plenty of them, so just trust me on that. If you have to get it fixed now, talk to Microsoft here.

the_doc