• Registered: 2008-07-10
  • Posts: 65

Topic: FF800: DPC Latency and dropouts

Hi, I've recently upgraded my motherboard and CPU and since then I have huge problems when playing back projects in Sonar. Every now and then the CPU usage went to more than 100% and massive crackles, even drop-outs occurred. With the old system I never had such problems.

The normal DPC Latency of this system is around 30-50 µs and there are no spikes at all. When playing back audio via my FF800 it goes up to around 500-600 µs and stays there (when the spikes happen, they're MUCH higher). This happens when using Sonar or Reaper (both ASIO) or even when just using Winamp (which uses DirectSound in this case). I've tried it with the on-board Firewire (VIA) and with a PCI Firewire card which has a TI chipset. In the latter case the on-board FW was disabled in BIOS. It's the same problem for both. I also tried to deactivate all energy saving options as well as Hyperthreading, on-board LAN, most USB devices etc. All the drivers on my system should be the most recent now.

Nothing seems to work.

The CPU and/or DPC spikes only happen when playing back audio and they come in irregular intervals. It can be 3 or 30 seconds, sometimes 30 minutes. LatencyMon shows "wdf01000.sys" as the culprit but my research has shown that this is just a low level kernel driver which other drivers use to access their hardware.

Now my questions:
1. Is it normal that the DPC Latency is going up this high when playing audio via Firewire (apart from the spikes)?
2. Is there anything else I can try to get rid of the CPU/DPC spikes or at least find out which driver really causes the spikes?

My system: i7 2600K, Asrock Z68 Extreme4 Gen3, 8 GB RAM, ATI Radeon 5770, FF800, 2 x UAD-2 Solo

fripholm's Website

  • Registered: 2011-05-04
  • Posts: 249

Re: FF800: DPC Latency and dropouts

Hi!
LatencyMon (google it for free download) will tell you which drivers are causing DPC latency, and sometimes it helps to troubleshoot.
My "educational guess" is video driver---or some BIOS setups around AHCI---so, the first thing I would try is to disable video driver for your card. Then system will use VGA driver (after rebooting, resolution will be 640x480), and check DPC latency again. If the video driver is the culprit, then you need to "work around" the updates, removing some add-on components (video driver installer installs lots of crap --for Audio). Or, in worst scenario, replace the video card. Another thing I realized in your system---Have you tried without UAD cards?

Good luck!

  • Registered: 2008-07-10
  • Posts: 65

Re: FF800: DPC Latency and dropouts

Thanks Masaaki! But you obviously didn't read my whole post as I mentioned LatencyMon which shows "wdf01000.sys" as the culprit (but this doesn't tell me too much as I mentioned as well). Additionally I can rule out any AHCI settings because I disabled them all for testing purposes to no avail.

The new CPU has an integrated GPU (which is disabled at the moment) but I will try it with this one and remove the ATI card and drivers for testing. Right now I'm also testing a project without any UAD plugins and I had no drop-outs for several minutes. Maybe it's the UADs but removing these is not an option.

Anyone else?

fripholm's Website

4 Reply by Masaaki (edited by Masaaki 2012-07-11 14:17:10)

  • Registered: 2011-05-04
  • Posts: 249

Re: FF800: DPC Latency and dropouts

Oh, I started writing my reply after reading the first two paragraph---fryingpan

  • Registered: 2012-01-08
  • Posts: 35

Re: FF800: DPC Latency and dropouts

Have you updated your systems BIOS by it's very most recent drivers?
That did the trick for me after an endless ordeal of dropouts.

Is your power supply sufficient for the new hardware parts?

Is your RAM up to speed with the new mobo?

My UAD 2 Solo Laptop card caused major problems as well, being not compatible with whatever bits of my hardware.
I've chosen not to use anymore on that system.
Probably not related to your problem, but UAD cards can be pretty bitchy at times and can bring otherwise healthy systems to their knees.

Good luck!

6 Reply by fripholm (edited by fripholm 2012-07-11 13:42:28)

  • Registered: 2008-07-10
  • Posts: 65

Re: FF800: DPC Latency and dropouts

Masaaki wrote:

Oh, I started writing my reply after reading the first too paragraph---fryingpan

No problem. :-)


Erbs Bischof wrote:

Have you updated your systems BIOS by it's very most recent drivers?
That did the trick for me after an endless ordeal of dropouts.

Yes, it's the latest. It was the first thing I did because the BIOS the new board shipped with didn't even allow Windows to start.


Is your power supply sufficient for the new hardware parts?
Is your RAM up to speed with the new mobo?

The PSU should be more than sufficient and the RAM is on the vendor's memory support list for this board - should also be well suited.


My UAD 2 Solo Laptop card caused major problems as well, being not compatible with whatever bits of my hardware.
I've chosen not to use anymore on that system.
Probably not related to your problem, but UAD cards can be pretty bitchy at times and can bring otherwise healthy systems to their knees.

Yeah, I've read that on the UAD forums in regards to v6.2 - maybe I should go back to 6.1 and try this instead. The UADs never caused any problems on the old system which also was Intel based (i5 750, Intel P55 chipset) with everything else pretty much the same.


Did anyone notice an extreme increase in DPC latency when playing back audio via a Firewire device?

fripholm's Website

  • Registered: 2011-05-04
  • Posts: 249

Re: FF800: DPC Latency and dropouts

fripholm wrote:

Did anyone notice an extreme increase in DPC latency when playing back audio via a Firewire device?

No, my system is X58A motherboard with i7 950, 12GB RAM, and DPC latency is around 20-30us by average. When I use Firewire interfaces (RME UFX, M-Audio Profire 2626, and Focusrite Saffire 24 DSP), it goes up to somewhere around 60-80us, but not like 400 or 500us.