DMA settings?

[Gary Fritz]

I get lousy response when my system is doing heavy disk or CD/DVD access.
When I'm burning a CD, the system becomes almost totally non-responsive.
It can take 5-10 seconds to respond to a keypress. Sure sounds like it's
running PIO.

I checked the DMA settings in the IDE/ATAPI controllers. The settings
were:

Primary Device 0: Use DMA if available; Current mode UDMA.
Primary Device 1: Use DMA if available; Current mode PIO. (!)
Secondary Device 0: Use DMA if available; Current mode PIO. (!)
Secondary Device 1: Use DMA if available; Current mode N/A

My system is an Asus A7V266-E mobo with 2 hard drives on the primary:
100GB Maxtor 6L100P0 on 0, 160GB WDC WD1600JB on device 1. There is a
CD/DVD burner on secondary 0: DigitalMax DRW-3s163.

Apparently DMA is enabled by the BIOS since Primary0 is using UDMA. What
do I have to do to get Primary1 and the DVD drive on Secondary0 to use DMA?

What transfer rate should I expect when DMA is enabled -- either between
Primary0 and Primary1, or intra-disk?

Thanks!
Gary

 

[Glen]

I get lousy response when my system is doing heavy disk or CD/DVD access.
When I'm burning a CD, the system becomes almost totally non-responsive.
It can take 5-10 seconds to respond to a keypress. Sure sounds like it's
running PIO.

I checked the DMA settings in the IDE/ATAPI controllers. The settings
were:

Primary Device 0: Use DMA if available; Current mode UDMA.
Primary Device 1: Use DMA if available; Current mode PIO. (!)
Secondary Device 0: Use DMA if available; Current mode PIO. (!)
Secondary Device 1: Use DMA if available; Current mode N/A

My system is an Asus A7V266-E mobo with 2 hard drives on the primary:
100GB Maxtor 6L100P0 on 0, 160GB WDC WD1600JB on device 1. There is a
CD/DVD burner on secondary 0: DigitalMax DRW-3s163.

Apparently DMA is enabled by the BIOS since Primary0 is using UDMA. What
do I have to do to get Primary1 and the DVD drive on Secondary0 to use DMA?

Try a better cable (80-pin, 40 conductor) for all devices.

Also check the settings for each device in your system bios setup.
Set all devices to Auto, or look up the specs for the drives and set
the UDMA mode for each one manually.

 

[MrC.]

You might try updating your chipset drivers... The ide controller normally
would select dma for the hard drives and you would only have to select it
for the optical drive.

 

[paulmd]

Try a better cable (80-pin, 40 conductor) for all devices.

That's backwards, 80 conductor, 40 pin. Just so OP doesn't get
confused.

 

[Gary Fritz]

That's backwards, 80 conductor, 40 pin. Just so OP doesn't get
confused.

It appears I already have 80-conductor cables, except for a 40-conductor
cable on the floppy drive. The DVD drive on Secondary (the worst offender)
is on the end connector, with no "stub" at the end.

You might try updating your chipset drivers... The ide controller
normally would select dma for the hard drives and you would only have
to select it for the optical drive.

I will look into that, but I know I updated the BIOS (and I think the VIA
chipset drivers) within the last 2 years. Considering this is a 5-yr-old
mobo, I would think that is current. The Asus support website is offline
today but I'll check for updates later.

Gary

 

[Glen]

Sorry, at least you knew what I meant.

It appears I already have 80-conductor cables, except for a 40-conductor
cable on the floppy drive. The DVD drive on Secondary (the worst offender)
is on the end connector, with no "stub" at the end.



I will look into that, but I know I updated the BIOS (and I think the VIA
chipset drivers) within the last 2 years. Considering this is a 5-yr-old
mobo, I would think that is current. The Asus support website is offline
today but I'll check for updates later.

What are the device settings in your system bios?

 

[Gary Fritz]

What are the device settings in your system bios?

I don't see any settings for DMA, except it says the Primary Master &
Secondary are PIO 4, UDMA 5. (What exactly does that mean? Are those
selection addresses, or...?) Those settings aren't changeable. The
Secondary Master was PIO 4, UDMA 4. I tried to change it to UDMA 5 to be
like the Primary, but when I rebooted it the device listing from the BIOS
still showed 4/4.

On another page the "I/O Device Configuration" was "ECP/DMA," Select = 3.
That's the only DMA-related stuff I can find.

The Asus support site is finally up again. The latest "official" BIOS
release is rev 1011, which is what I'm running. There is a more recent rev
(dated 2003) but it's a "Beta." I don't see a version for my VIA chipset
drivers, but the latest one is dated early 2002. That's earlier than the
1011 BIOS rev so I'm 99% sure I got them both.

Gary

 

[Gary Fritz]

Well, I resolved my problem, although I *DO NOT* recommend my method...

I added some RAM -- top-grade Crucial 1GB sticks -- and ran them through a
6-hour torture test to make sure there were no compatibility problems. But
as soon as I brought up Windows, wham! It crashed bigtime. End result was
that I blew up my registry, and had to revert to an 8-month-old backup from
right after I installed the system.

So with some work I'm almost back to functional again. And guess what, I
checked Primary1 and it's UDMA now! Secondary0 was PIO but I changed it to
"UDMA if available" and, after a reboot, now it's UDMA too. I can burn a
CD and not even notice it.

Nice to know SOMEthing good came out of that disaster!!!
Gary

 

[Gary Fritz]

Sorry to resurrect an old thread, but I figured it might be simplest...

As I posted back in May (below), my PIO/DMA problem was resolved after I
blew up my registry and rebuilt it from a right-after-fresh-install
registry backup. All I had to do was set my drivers to "UDMA if
available" and everything worked just as it was supposed to.

Well, it's two months later, and a few days ago when I rebooted I got
some message about being unable to turn on DMA. I accidentally cleared
the error message without seeing exactly what it said, and it hasn't
appeared since. Sure enough my CD/DVD drive (on Secondary0) is now
running in PIO mode, even though it's set to "UDMA if available" and even
though it was working in DMA mode until last week. Rebooting doesn't
help anything -- it's still running PIO.

What would cause it to revert to PIO after it had been running just fine
with UDMA for 2 months?? How do I fix it?

Thanks,
Gary

 

[Glen]

Sorry to resurrect an old thread, but I figured it might be simplest...

As I posted back in May (below), my PIO/DMA problem was resolved after I
blew up my registry and rebuilt it from a right-after-fresh-install
registry backup. All I had to do was set my drivers to "UDMA if
available" and everything worked just as it was supposed to.

Well, it's two months later, and a few days ago when I rebooted I got
some message about being unable to turn on DMA. I accidentally cleared
the error message without seeing exactly what it said, and it hasn't
appeared since. Sure enough my CD/DVD drive (on Secondary0) is now
running in PIO mode, even though it's set to "UDMA if available" and even
though it was working in DMA mode until last week. Rebooting doesn't
help anything -- it's still running PIO.

What would cause it to revert to PIO after it had been running just fine
with UDMA for 2 months?? How do I fix it?

Depends what's causing the problem.

Check the device settings in your system bios.

Reinstall your motherboard's chipset drivers.

Try a different cable.

Reinstall service pack 4.

 

[Gary Fritz]

Depends what's causing the problem.
Check the device settings in your system bios.
Reinstall your motherboard's chipset drivers.
Try a different cable.
Reinstall service pack 4.

BIOS settings, cables, chipset drivers, etc have not changed in the last
week. Why would it suddenly stop working?

Maybe Windoze itself has just gotten hosed and reinstalling SP4 might help,
but I would like to think there was a more logical answer. If it is truly
a case of Windows getting its knickers in a twist, then why would just
reinstalling SP4 solve it? Maybe I have to revert back to a pristine
registry again to solve it, like I did in May? And if so, then it might
still only last 2 months like it did this time?

I'd like to know what CAUSED the change so I can fix it. Or at least know
what registry setting is getting zorched so I can repair it without having
to reinstall or revert to an old registry.

Gary

 

[Glen]

BIOS settings, cables, chipset drivers, etc have not changed in the last
week. Why would it suddenly stop working?

Maybe Windoze itself has just gotten hosed and reinstalling SP4 might help,
but I would like to think there was a more logical answer. If it is truly
a case of Windows getting its knickers in a twist, then why would just
reinstalling SP4 solve it? Maybe I have to revert back to a pristine
registry again to solve it, like I did in May? And if so, then it might
still only last 2 months like it did this time?

I'd like to know what CAUSED the change so I can fix it. Or at least know
what registry setting is getting zorched so I can repair it without having
to reinstall or revert to an old registry.

If you don't know what caused it, chances are virtually nil a
stranger on usenet will know.

Just from my own experience this change occurs either because
of flaky hardware (Windows does a bus test every time it boots,
and if any part of the IDE chain (devices, cables etc) fails a
DMA transfer test it'll revert to PIO mode), or poorly written
IDE and/or chipset drivers (e.g. older mainboards with Via and
Apollo chipsets are notorious for this). But a dozen other causes
are possible as well. Virus infection, third-party drivers or other
software etc.

 

[Gary Fritz]

Just from my own experience this change occurs either because
of flaky hardware (Windows does a bus test every time it boots,
and if any part of the IDE chain (devices, cables etc) fails a
DMA transfer test it'll revert to PIO mode), or poorly written
IDE and/or chipset drivers (e.g. older mainboards with Via and
Apollo chipsets are notorious for this).

Umm. That makes sense. It's certainly possible the hardware is flaky
-- it's a no-name DVD-RW from Best Buy. The mobo is an Asus A7V266-E
with Via chipsets, but I'm 99% sure I have the latest drivers.

Presumably if the DVD-RW failed a boot-up test, the system records that
in the registry and never tries again. If the DVD-RW is iffy, it would
be simple enough to clear the DMA-failure flag any time Windows decided
it didn't like it.

OK, I dug around in the registry for a while without finding any obvious
answers. Then I went hunting on the web again, and hit paydirt:

http://winhlp.com/WxDMA.htm

This site describes this exact problem. It's aimed at XP but it says it
also works for w2000. As described about halfway down on that page, I
went to HKLM\SYSTEM\CurrentControlSet\Control\Class\{4D36E96A-E325-11CE-
BFC1-08002BE10318} and found my secondary IDE channel. I deleted
MasterIdDataChecksum (there was no SlaveIdDataChecksum since I have no
slave device on that channel) and rebooted.

Shazam! My DVD-RW is running UDMA again!

Apparently this problem can be triggered by something as simple as a
scratched CD or DVD. Lovely that Windows decides to permanently disable
DMA just because of a media problem. But at least now I know what's
causing it and how to fix it, without reinstalling anything.

Thanks for pointing me in the right direction!
Gary

 

[Glen]

Umm. That makes sense. It's certainly possible the hardware is flaky
-- it's a no-name DVD-RW from Best Buy. The mobo is an Asus A7V266-E
with Via chipsets, but I'm 99% sure I have the latest drivers.

Presumably if the DVD-RW failed a boot-up test, the system records that
in the registry and never tries again. If the DVD-RW is iffy, it would
be simple enough to clear the DMA-failure flag any time Windows decided
it didn't like it.

OK, I dug around in the registry for a while without finding any obvious
answers. Then I went hunting on the web again, and hit paydirt:

http://winhlp.com/WxDMA.htm

This site describes this exact problem. It's aimed at XP but it says it
also works for w2000. As described about halfway down on that page, I
went to HKLM\SYSTEM\CurrentControlSet\Control\Class\{4D36E96A-E325-11CE-
BFC1-08002BE10318} and found my secondary IDE channel. I deleted
MasterIdDataChecksum (there was no SlaveIdDataChecksum since I have no
slave device on that channel) and rebooted.

Shazam! My DVD-RW is running UDMA again!

Apparently this problem can be triggered by something as simple as a
scratched CD or DVD. Lovely that Windows decides to permanently disable
DMA just because of a media problem. But at least now I know what's
causing it and how to fix it, without reinstalling anything.

Thanks for pointing me in the right direction!
Gary

Ur welcome. You might want to double-check for
updated Via drivers even though the issue is resolved.