High DPC Latency and Slow Hard Pagefaults on Gigabyte GA-EP35C-DS3R Motherboard

I've owned a DIY-built PC on a Gigabyte GA-EP35C-DS3R motherboard for
about 2 years now. When I first built this PC, it ran perfectly under
Windows XP 32-bit. Performance was good, and I had no issues with
freezeups or audio distortion. I recently upgraded to Windows 7 64-
bit, and since then, I've had serious performance problems. The system
occasionally freezes up, usually for only a second but sometimes for
more than 15 seconds. I get distortion in audio playback through the
onboard Realtek Azalia HD-Audio, which sounds like the audio is frozen
on a single tone for half a second or more, turning it into a buzzing
sound. Video playback stops and stutters every few seconds as well.
Disk and network performance are also significantly worse than under
Windows XP. I get 2D graphics slowdowns drawing simple windows, like
something out of 1995.

I've done research on my issues and found that they seem to relate to
problems with driver DPC latency and hard pagefaults. I've been using
the DPC Latency checker from http://www.thesycon.de/deu/latency_check.shtml,
and I see frequent spikes of latency over 4ms. Baseline latency is
rarely lower than 0.5ms, and is usually around 1ms idle, closer to 2ms
when working. I've also used the Latency Monitor tool at
http://www.thesycon.de/deu/latency_check.shtml, and it's reported hard
pagefaults longer than 500ms, and DPC latency of over 2.3ms in
netbt.sys.

I've tried disabling EIST and C1E in BIOS, and this helped a little
bit. Disabling the onboard ethernet, sound, or USB also helps, but
this is unacceptable, as I require all of these functions.

Before anyone asks, I've spent weeks ruling out other possible causes.
I've malware and spyware scanned with four separate programs. I've
chkdsked, defragged, cleared temp files, rebuilt page files, and swept
my registry for errors with two different programs. I've disconnected
every piece of hardware I could, checked every internal connection,
checked my memory for errors with Memtest86+ for a whole weekend while
I was out of town, run CPU burnin programs, swapped most of the
cables, and even moved my RAID from the Intel Matrix controller to the
GBB36X controller. I have a copy of Fedora 13 (GNU/Linux) on another
boot drive which runs perfectly and extremely fast on this hardware.
There's something about the way Windows 7 interacts with this
motherboard.

I've seen that other similar Gigabyte P35 motherboards have had this
issue, and some have been helped by BIOS updates.

http://forum.cakewalk.com/tm.aspx?m=...e=1&key="

http://forums.tweaktown.com/gigabyte...piking-19.html

http://forum.cockos.com/showthread.php?t=20413

I have the latest BIOS for my motherboard, which does not appear to
have had an update from Gigabyte regarding this issue. I've filed a
ticket with them in hopes that they can help.

Does anyone have any suggestions to how I might recover? I really
don't want to roll back to Windows XP!

Ryan wrote:
I've owned a DIY-built PC on a Gigabyte GA-EP35C-DS3R motherboard for
about 2 years now. When I first built this PC, it ran perfectly under
Windows XP 32-bit. Performance was good, and I had no issues with
freezeups or audio distortion. I recently upgraded to Windows 7 64-
bit, and since then, I've had serious performance problems. The system
occasionally freezes up, usually for only a second but sometimes for
more than 15 seconds. I get distortion in audio playback through the
onboard Realtek Azalia HD-Audio, which sounds like the audio is frozen
on a single tone for half a second or more, turning it into a buzzing
sound. Video playback stops and stutters every few seconds as well.
Disk and network performance are also significantly worse than under
Windows XP. I get 2D graphics slowdowns drawing simple windows, like
something out of 1995.

I've done research on my issues and found that they seem to relate to
problems with driver DPC latency and hard pagefaults. I've been using
the DPC Latency checker from http://www.thesycon.de/deu/latency_check.shtml,
and I see frequent spikes of latency over 4ms. Baseline latency is
rarely lower than 0.5ms, and is usually around 1ms idle, closer to 2ms
when working. I've also used the Latency Monitor tool at
http://www.thesycon.de/deu/latency_check.shtml, and it's reported hard
pagefaults longer than 500ms, and DPC latency of over 2.3ms in
netbt.sys.

I've tried disabling EIST and C1E in BIOS, and this helped a little
bit. Disabling the onboard ethernet, sound, or USB also helps, but
this is unacceptable, as I require all of these functions.

Before anyone asks, I've spent weeks ruling out other possible causes.
I've malware and spyware scanned with four separate programs. I've
chkdsked, defragged, cleared temp files, rebuilt page files, and swept
my registry for errors with two different programs. I've disconnected
every piece of hardware I could, checked every internal connection,
checked my memory for errors with Memtest86+ for a whole weekend while
I was out of town, run CPU burnin programs, swapped most of the
cables, and even moved my RAID from the Intel Matrix controller to the
GBB36X controller. I have a copy of Fedora 13 (GNU/Linux) on another
boot drive which runs perfectly and extremely fast on this hardware.
There's something about the way Windows 7 interacts with this
motherboard.

I've seen that other similar Gigabyte P35 motherboards have had this
issue, and some have been helped by BIOS updates.

http://forum.cakewalk.com/tm.aspx?m=...e=1&key="

http://forums.tweaktown.com/gigabyte...piking-19.html

http://forum.cockos.com/showthread.php?t=20413

I have the latest BIOS for my motherboard, which does not appear to
have had an update from Gigabyte regarding this issue. I've filed a
ticket with them in hopes that they can help.

Does anyone have any suggestions to how I might recover? I really
don't want to roll back to Windows XP!

When is the last time you tested your hard drive ?

Any chance you've got a lot of bad blocks ?

Run the disk manufacturer's diagnostic, if you can find one.

*******

As I understand it, some of those DPC issues, were due to too much
time spent in SMM. But your symptoms suggest something much
worse than that.

http://en.wikipedia.org/wiki/System_Management_Mode

Exactly why SMM might be used, what firmware function might use
it, I haven't a clue.

Paul

On Sep 27, 10:02*pm, Paul wrote:

When is the last time you tested your hard drive ?

Any chance you've got a lot of bad blocks ?

Run the disk manufacturer's diagnostic, if you can find one.

I'll give it a run through Spinrite tonight, see what it shows.


*******

As I understand it, some of those DPC issues, were due to too much
time spent in SMM. But your symptoms suggest something much
worse than that.

http://en.wikipedia.org/wiki/System_Management_Mode

Exactly why SMM might be used, what firmware function might use
it, I haven't a clue.

From what I've gathered on other forums, the issue probably relates to
Gigabyte's Dynamic Energy Saver features, where the CPU is supposed to
scale up and down to save power when not busy. It seems that this
worked fine in Windows XP, was patched to work under Vista, but broke
again under Windows 7. Also, their utilities to manage these features
don't work on Windows 7, they produce constant BSODs in gdrv.sys when
installed.

--Ryan