MVP service causing PC stutter

[wtg]

I recently started using a couple MVP's, and they're great. However, I run into a problem that I can't find a way to cure.

I've been noticing a stutter while watching movies on the gbpvr PC and have finally tracked it down. When either MVP is turned on but not being used, every five seconds on the PC one of the MVP services spikes the CPU. It doesn't seem to hit it too hard, anywhere from 35-42% utilization, but it definitely introduces a noticable and irritating stutter in the video playback on the host PC (sound is fine). The strange thing is that my CPU utilitization during playback only uses about 25-30% of the CPU, so it would seem that the two running together shouldn't have a problem since it still doesn't get anywhere near 100%. But it also doesn't seem like the service should use anything like that much CPU when it's not doing anything either other than, I assume, polling for input. If I turn the MVPs off, the periodic CPU spike disappears.

Does anyone have any suggestions? Sub, is there any chance that the MVP service isn't yielding like it should and so holding on to the CPU just a tad more than it should?

Thanks,
Tim

[AOSandman]

This is caused by the "Recording Now/Next" widget on the main menu. You can turn it off by editing the main menu skin. Look for the special element panel "NextRecording" and set visible to false.

Alternately (but not as clean), just leave your MVP(s) on some other menu (like the Recordings menu) when not in use.

[wtg]

This is caused by the "Recording Now/Next" widget on the main menu. You can turn it off by editing the main menu skin. Look for the special element panel "NextRecording" and set visible to false.

No kidding?!? I can't wait to go home and try it. I'm not sure why a simple screen refresh would be so intensive but if that's all it takes to let me keep the MVPs turned on, it's sure a simple work-around.

Thanks for the reply.
Tim

[sub]

Let me know if it corrects you problem. If it does seem to be the source, I'll see if I can find a fix. I'm surprised though, its doing very little when it updates the now/next. I'll also try it here.

[AOSandman]

Sub,

Does the MVP server check the DB at each screen refresh? Maybe the combo of disk IO and CPU usage, multiplied over several MVP servers, is enough to affect other processes? Just speculating, but turning off the widget definitely helped here.

[sub]

Does the MVP server check the DB at each screen refresh?

Only if the date time on the gbpvr.mdb file has been changed.

[wtg]

AOSandman,

Your advice was right on. Like you said, if I had the MVP's sitting on a different screen than the main menu, the problem disappears. Then, when I turned off the "NextRecording" feature in the skin the performance problem disappeared completely. Now I'm just going to search the forums until I figure out how to have a different skin for the MVP versus the PC.

Sub, I have some more information for you regarding the problem. I got to thinking today that the CPU utilization I was seeing was still too small to account for the stutter I've been seeing during playback. I was just using taskman to determine the CPU use, with it's default polling of about once a second. I thought perhaps the CPU percentage was really going higher than the observed 40% or so but it was staying there so briefly that I wasn't seeing it. So I turned up the taskman polling frequency to it's highest setting. Look at the graph.

CPU Utilization w/Next Recording

At this polling frequency I was seeing short spikes of 70-90% CPU utilitization with no other process on the system doing anything.

Next, after removing the NextRecording panel, look at the graph. The CPU utilization goes to almost 0.

CPU Utilization w/o Next Recording

By the way, for point of reference on my machine the CPU utilization for the gbpvr process while serving a movie to the MVP runs around 4-6%. I don't know what's going on during the time the NextRecording panel is updated, but whatever it is, my machine sure doesn't like it. If there's anything you'd like me to do or logs you'd like me to post or whatnot, I'd be happy to oblige.

Thanks,
Tim

[sub]

wtg, what spec is your machine?

[wtg]

wtg, what spec is your machine?

It's not particularly beefy.

1.1 GHz Celeron, 512 meg of ram, 1Gb lan, 600GB disk space.

For reference, playback of a DVD-quality mpeg on the machine itself runs about 25-35% CPU utilization.

Tim

[sub]

I'm guessings its just a bit too much for your machine. The recommended minimum for GB-PVR was a 1Ghz PIII class CPU or higher, and when you use an MVP it requires a bit more again. It looks like the flurry of activity required to generate and send the updated screen to MVP every so often is requires a bit too much CPU, disrupting other things going on PC.

I'd say the 'next recording' is just the first time you've noticed this. I'd guess that even if you disabled the next recording screen, the PC would be disrupted by anyone using the MVP at the same time (regardless of screen).