Incredibly high cpu during live TV

[ubu]

I've searched all the relevant threads but can't find anyone with cpu levels as high as I am experiencing. I've tried various permutations of drivers, decoders, config options, etc. and, while I've learnt a lot about how flexible GBPVR is, I can't seem to nail down the cause of near 100% cpu use while watching live (or timeshift) TV. The symptoms (probably obvious) - very slow OSD and channel switching, jerky playback when viewing mini guide and varying degrees of audio delay. Here's what I get:

GBPVR menu: 1 to 5%
Video playback: 55 to 65%
Recording: 60 to 70%
Live TV: 85 to 99%

These numbers seem wildly higher than those other people have described (even when complaining about high cpu use). The only background processes running are GBPVR recording service, irremote, wireless LAN and XP remote terminal (my PVR is headless). In any case, the cpu load while at the main menu shows it as virtually idle. A P4 2.4ghz with 512gb of RAM should not be this stressed, I surmise.

I am running the nVidia video and audio decoder. When I switch back to the Contour Non-CSS decoders that came with my PVR-150, the numbers drop slightly but not by much. (The nVidia PureVideo decoder is reputed to be a bit cpu hungry, I gather).

I'm using the standard Hauppauge (orange label) driver. I'm hesitant to switch to the latest version due to the recent discussions about the timeline issues et al.

I'm getting pretty desperate.:confused: I seem to have tried everything I can think of. Before I have to accept the inevitable and re-install everything (clean XP install and build GBPVR back up step at a time), does anybody have any suggestions of possible causes or other things to check/try?

[Chris.Day]

Download Process Explorer and see what is generating the high CPU usage. When recording (and not watching) CPU usage should be minimal. I'd suspect some driver/interrupt problem if it's that high. Process Explorer will tell you which process it is.

[ubu]

Checked out Process Explorer. Handy tool. Thanks for the tip. I'll install it and see if it gives me a clue. Are you thinking I might be suffering from some kind of driver conflict? Or a hardware interrupt conflict? If the latter, I'm not clear if it would show up in Process Explorer. I did move my PVR-150 and my wi-fi card to different slots a few weeks ago (wi-fi antenna kept getting tangled in the a/v cables) so that's a possibility. Any idea how I'd find out if the IRQs are hosed up? Nothing obvious in Device Manager that I can see.