Once in a while, Windows seems "choppier" than it should be. It's as if everything is running at a lower "framerate", but the on-paper framerate of games and other programs does not drop during this time (games still report 60 FPS, for example.) The sensation is clearly that of a much lower framerate, say 15-20 FPS, in all games and programs, even the Windows environment itself. These bouts of slowdown come and go at complete random, last for varying amounts of times (sometimes just 20-30 seconds, other times upwards of 10 minutes) and are not correlated to any one program, nor are they a byproduct of high CPU or RAM usage.
I can't possibly be the only one who's been frustrated by this sort of issue, yet I've searched and searched this place and found no similar questions/resolutions. In any case, this "lag" makes certain applications borderline unusable. And I've noticed this phenomenon on several different computers, but this one is the worst in this regard. HP EliteBook 8740W, Core i5 560M, 4GB RAM, 120GB SSD, ATI FirePro M7820 graphics. Completely stock with the original BIOS version, although I have reinstalled Windows 7 in the past.
LatencyMon shows a highest interrupt-to-process latency of over 32,000 μs. The highest DPC time is normally in the four-figures, and nine times out of ten is caused by NDIS.SYS.
That led me to believe that it's a network card causing the problem. Well, I've disabled both the wireless adapter and ethernet card, and I've updated and rolled back and updated the drivers for both of them, to no avail. I've tried disabling and updating other devices like the card reader and sound device, but not the graphics driver as I actually sort of need that. I actually sort of need the audio and wireless drivers as well, but it's easier to re-enable a device when you actually have some sort of video output.
Does it sound like a hardware issue, or a Windows one, or a driver one? And is there anything at all I could do to fix it? It has driven me insane since the beginning of time. Any suggestions on how to remedy this mysterious "lag", no matter how ridiculous it seems, would be welcome at this point.