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how to enable DMA(stuck in PIO mode) in XP

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TASL

ISP
Mar 27, 2002
4
CA
Help!, I've figured out why I'm getting buffer underruns

on my system, md CD-R is stuck in PIO mode, I'm running Windows XP, with a LG CED-8120B cd-rw drive, I have it selected to use dma if avaialbe, but its stuck in PIO mode, In 98 I can enable DMA no problem on the drive, just no in XP, I know there is suppoed to be a fix for this somewhere, can anybody help?
 
Are you sure that drive actually supports DMA, being able to enable it in 98 is no guide as 98 will allow this even if the drive does not support it and it may even work ok although you will possibly strike problems with stability
 
Here are the hard facts:


SPECS from this page (partial list of the DRIVE MODE)

SPECIFICATION
Transfer Rates Write Read CD-RW: 8X (1200 KB/sec)
CD-R: 12X (1800 KB/sec), 8X, 4X, 2X
32X MAX (4.8 MB/sec)CD-ROM

**** Data Transfer Rate(Burst) 16.67 MB/sec (PIO mode 4)
16.67 MB/sec (Multi-data mode 2) ******

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>.

That is the relevant part.
Now,,,,, what the heck is "Multi-data mode 2" ?????

Usually they are just listed as:
ATA/33
UDMA/33
( now, ATA/33 is UDMA 2 , so is this the same ?)

ATA/33 = 2
ATA/66 = 4
ATA/100 = 5
ATA/133 = 6
However, I am not familiar with the use of the term
"Multi-data mode"
 
Okay, after much searching, it seems XP (or my drive) has a bug when it comes to recoginzing certain drives as having DMA capability, and sticks it as PIO mode, which really is rotten, because when its in this mode, it is a huge cpu hog, when reading at faster than about 10x, it uses almost 100% cpu usage, no wonder it took an hour to install 3 cd's, and it gives me buffer underruns at 12x burns! It turns out, that you actually have to remove a entry in the registry, for Windows XP to enable the multi dma mode 2, once I did that, it worked much better, when reading it only uses about 10% cpu now, and I can burn at 12x no problem, and it took about a quarter of the same time to install those cd's

Thanks
 
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