After a clean boot, there isn't a problem with the sound. After a while of uptime (less than a day for sure, usually somewhere around eight hours), there will start to be an extremely noticeable problem with the sound. When playing music, it will sound like it has buffering problems, as well as playing at a slightly slower speed than normal. Looking at a latency checker (using DPC Latency Checker), the latency will be in the red, usually over 16000µs. This occurs whether I am using the STX or the onboard audio (I tried removing the STX card altogether for a week with the same results).
I will also get a very slight but noticeable stutter with the video at regular intervals (I mostly notice this in-game, but the mouse pointer will stutter going across the desktop as well).
As soon as I reboot, the problem disappears for a few hours.
I've updated the BIOS, tried rolling back to the drivers that came with my GTX 780, tried the most recent Nvidia drivers, tried the beta Nvidia drivers, disabled all audio drivers in device manager and tried only one at a time.
None of these have worked.
I have also run Prime95 and done a Memtest, neither of which found any issues.
