GA-X58A-UD3R r.2 DPC latency problems causing audio stutter

[kalniel]

Hi all,

I'm also suffering from high DPC latency with my new setup (sig for specs). The problem is best described in the following thread I found when searching:
http://forum.giga-byte.co.uk/index.php/topic,2166.0.html

At rest, my DPC latency is a super low 17 micro-seconds, great. But after a while of playing some games, like Torchlight, it becomes a solid block of 29k micro-seconds and causes stuttering problems, especially with audio. It looks a bit like this (taken from the thread above):
http://img121.imageshack.us/img121/613/dpcissues.png

I have a real problem trying to reproduce it for starters - it doesn't stutter as soon as I start a game, but some time afterwards. DPC latency can continue for a while after I have closed the game. Yet I can't seem to provoke it outside of a game - I've tried furmark and prime95 to really heat things up and I can't see a problem.

The solutions there and on other threads searched include trying a specific bios for a UD5 and 7 motherboards, disabling DES, disabling easy tuner, disabling SLI, tuning off all unnecessary processes, cooling the northbridge etc.

Unfortunately I've seen threads suggesting the latest BIOS for UD3R rev2 doesn't help the issue and I don't want to risk a BIOS update unless I'm sure it'll have a positive benefit. I didn't install easy tuner, disabling DES made no difference, I don't have SLI. I've only just installed Windows 7 so haven't played about with processes and don't know which ones to disable, I've tried disabling Anti virus, and all the motherboard bits I'm not using (like LAN, audio, gigabyte sata ports etc.) I've disabled in BIOS. I can't see any reason why my northbridge would be getting too hot - temperatures are good in general (the HAF912 is quite airy) - I could buy a side fan I guess, but again I don't really fancy throwing money at 'maybe' solutions, and I couldn't replicate the problem using the benchmarks that really heat the computer up (more than in games). Is there a software tool for NB temps anywhere? I've been using RealTemp for CPU temps. All network, graphics and audio drivers are at their latest versions.

I have noticed that my wireless NIC is sharing an IRQ with my audio card, but while that might have been a ye-olde-days cause for concern, it appears such sharing is entirely normal, perhaps even deliberate, and in no way is it user controllable.

Are there any other suggestions? Would undervolting the northbridge (however I do that) help? Would increasing the voltage to it help? I've tried setting the overall performance profile to standard, and setting voltages across the board to normal rather than auto. Memory is set to XMP, and computer is completely stable otherwise as far as I can tell.

Thanks in advance!

[Dark Mantis]

The thing is you have to understand you adversary to beat it. Latency is caused by bad programming generally. There are various rules for how a program should access the core and if it doesn't follow these rules it can result in the core not being released for the next operation and this causes a bottleneck that backs up. The biggest headache from our perspective is that we have to find the rogue program/driver. You seem to have narrowed it down to this game so that should make it easier for you. See if there are any patches for the game or any new drivers that the game tends to use.

[kalniel]

Unfortunately it's not just one game, that was just an example. I can also trigger it with NFS:Shift, Fallout 3, Crysis Warhead and probably others. But it doesn't always trigger.

[Dark Mantis]

In that case you are in for some extensive testing. You can try going into Device Manager and disabling everything you don't need to run the system and then running the latency checker and see if, by enabling one thing at a time, you can find the problem device.

Otherwise go to Task Manager/Processes and again disable anything not critical to running and see if you can locate the culprit.

Good luck.

[kalniel]

Hmm. Process killing didn't help, though I found one possible cause - I could replicate a 10k spiking by running prime95 large FFTs + furmark post process AND turning DES2 off. Eventually the NB I guess would heat up and the DPC latency would hit 10k in a solid block. However simply cutting the voltage a little to the IOH prevents this from happening, which DES2 was able to do, or via BIOS if DES2 was turned off.

I couldn't catch the 29k spiking cause though. Running with the side of the case off so that I could monitor LEDs possibly reduced the problem to the extent I didn't notice it affecting audio, although the logs showed DPC latency had still hit 29k.

I moved the audio card to a new slot, but as expected this didn't affect the IRQ assignment.

Are there any tools to monitor NB temperature? I notice MCH is displayed in the BIOS temperature section, but I can't see a way of accessing this once in windows.

[Dark Mantis]

I think Everest monitors the Northbridge.

[Lsdmeasap]

YesDM is correct, Everest Ultimate, AIDA64, or HWmonitor (TMPIN2) will all show you the IOH temps (NB)