I have had the same soundcard for a while and had all kind of glitches as well. If you search in the m-audio forums you will see lots of people with the same problems.

However, there is a way to minimize the glitches. In my case they never went fully away.

Try this:
- Go into your bios and disable hyper threading
- Disable C1E state if possible
- Disable all other CPU energy saving features

Good luck.

cheers

I have a Core i7-2600K (4 core + HT) that runs from 1.6kHz and 4.2kHz, though when Pianoteq is the only program it seldom goes above 3kHz.

I think your processor is running a little slow.. Kilohertz? :-) I'm kidding.. of course you meant GHz.

I think you've ruled out all the usual suspects. The answer is probably obscure.

Can you look at the CPU graph inside Pianoteq and see if it spikes when you hear the pops? I used to have issues with the multi-core rendering and CPU overload protection settings. Experimenting with those two settings sometimes affected the popping, but that was several versions ago.

It's been a while since I've used Windows much. Would adjusting the process priority have any affect? Probably not, if you're not doing much else when you use Pianoteq..

Also, if you have another audio device (built-in, USB, etc) try comparing with that. That would rule out your audio interface.

Good luck!

Internal       Host      Buffer
----------------------------------------------------------------------
44.1kHz    44.1kHz      64     Very sparse audio glitches (minutes)
48kHz       48kHz         64     Very sparse audio glitches

44.1kHz    44.1kHz    128     Very sparse audio glitches
44.1kHz    88.2kHz    128     Almost constant audio glitches (seconds)
48kHz       48kHz       128     Very sparse audio glitches
48kHz       96kHz       128     No glitches

44.1kHz    44.1kHz    256     Very sparse audio glitches
44.1kHz    88.2kHz    256     Almost constant audio glitches
48kHz       48kHz       256     Very sparse audio glitches
48kHz       96kHz       256     No glitches

44.1kHz    44.1kHz    512     No glitches
44.1kHz    88.2kHz    512     Almost constant audio glitches
48kHz       48kHz       512     No glitches
48kHz       96kHz       512     No glitches

44.1kHz    44.1kHz   1024    No glitches
44.1kHz    88.2kHz   1024    Sparse glitches (a couple a minute)
48kHz       48kHz      1024    No glitches
48kHz       96kHz      1024    No glitches

The performance index will show from 34 to 37.  Enabling and disabling Multi-core seems to have no effect.  The Audio Load graph will show a orange or red line in the graph when I hear a pop.  The other frequencies don't really improve much till 512 samples.  44.1kHz@88.2kHz doesn't improve till 1024 samples.  During it all, the CPU is very controlled and not much is going on IO wise.  The 48kHz based rates always seem just a hair more stable, not sure why.  Has anyone seen anything like this?  The pops are driving me batty.

I have a Core i7-2600K (4 core + HT) that runs from 1.6kHz and 4.2kHz, though when Pianoteq is the only program it seldom goes above 3kHz.  16GB of RAM, so not swapping etc.  The thing that strikes me a bizarre is that usually this sort of thing is from having too short of a buffer, and running at 96kHz with 48k internal seems to be the smoothest.  Unfortunately most of my projects are 44.1kHz, so this tweak only helps the standalone run smooth.

Thanks,
   -Eric

PS - Version 3.6.8/20120116