<div><span class="gmail_quote">On 5/2/08, <b class="gmail_sendername">Mark Knecht</b> <<a href="mailto:markknecht@gmail.com">markknecht@gmail.com</a>> wrote:</span>
<blockquote class="gmail_quote" style="PADDING-LEFT: 1ex; MARGIN: 0px 0px 0px 0.8ex; BORDER-LEFT: #ccc 1px solid">On Wed, Apr 30, 2008 at 7:18 AM, Mark Knecht <<a href="mailto:markknecht@gmail.com">markknecht@gmail.com</a>> wrote:<br>
> I'm flummoxed about 0.21 and all the stuttering problems we're having.<br>> Here's the set of experiments I've done:<br>><br>> The system:<br>><br>> 1) The backend - dedicated backend machine is an AMD Sempron 3200+,<br>
> with SATA drive & 512MB. hdparm -tT says 45MB/S. After a boot I'm<br>> using 180MB of ram. No swapping has been reported.<br>><br>> 2) Local frontend - underpowered 1.8GHz Celeron with 256MB, but shared<br>
> memory with the graphic controller so only about 185MB.<br>><br>> 3) Remote frontend #1 across wireless network - AMD64 3000+ with 1GB memory.<br>><br>> 4) Remote frontend #2 across wireless network - identical to local<br>
> frontend - 1.8GHz Sempron with 256MB.<br>><br>> The results:<br>><br>> 1) On the local frontend I can run live TV or recorded material<br>> without any stuttering.<br>><br>> 2) On remote frontend #1 (the AMD64) I can run live TV without<br>
> stuttering but all recorded material stutters badly. The AMD64 is<br>> running the SLIM profile.<br>><br>> 3) On remote frontend #2 I have no problems. Live and recorded<br>> material playback fine.<br>
><br>> Prior to switching to 0.21 we had no problem with any machine. Since<br>> switching to 0.21 my AMD64 machine is useless.<br>><br>> CPU usage on the backend is never more than 2% when it's only doing<br>
> playback. On the AMD64 CPU usage as reported by top is never more than<br>> 20%.<br>><br>> Here's the one that really bothers me: On the AMD64 I can play live TV<br>> with a full system rebuild going on - compilers are running and CPU<br>
> usage as reported by top is 100%. Disk usage is intense at times. Live<br>> TV is perfect. No stuttering. On the other hand with absolutely<br>> nothing running on the AMD64 playback of recorded material stutters<br>
> all the time.<br>><br>> I cannot figure out where the weak link is.<br>><br>> Any ideas anyone?<br>><br>> Thanks,<br>> Mark<br>><br><br>OK, so no one has any ideas yet. Hopefully this info will help:<br>
<br>1) While running the AMD64 frontend in Linux I ran mythfrontend and<br>along side it ran top. When I first start playback it is at regular<br>speed and top shows 10% CPU usage. At this point I can play recorded<br>material without much stuttering. It's almost as good as live TV, but<br>
not quite.<br><br>2) As is my custom I typically watch recorded TV shows 10% fast. ('a'<br>key, right arrow twice) With 0.20 I could do this and there was no<br>noticable change in CPU usage. It stayed in the 10-12% range. With<br>
0.21 the CPU usage jumps to over 20% and this is when the stuttering<br>gets really bad on this machine.<br><br>3) When I drop the speed back to normal ('a' key - left arrow twice)<br>the CPU usage stays at 20%. Nothing I do makes it come back to 10%<br>
like it is when I tart clean. At this point the frontend still<br>stutters.<br><br>As an additional test I boot the same machine into Windows XP. In XP<br>the MythTV player application stutters just like Linux but it does it<br>
at normal speed. I get messages about rebuffering.<br><br>On this same machine in Windows XP the NetFlix Instant Watch player<br>plays fine for hours without stuttering or rebuffering.<br><br>Unfortunately this machine has an ATI controller in it so I'm not able<br>
to do XvMC, as far as I know. If there are accelerations I can enable<br>I'd like to find some instructions on doing so.<br><br>Thanks,<br>Mark<br>_______________________________________________<br>mythtv-users mailing list<br>
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<div><br>You haven't indicated what type of material you are recording / playing. Assuming it is SD, I would say that even at 20% your system should be able to perform decent playback. I would suspect the problem is related to using a wireless network. Just to test, try connecting that frontend via Cat5.</div>
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<div>I am no expert on Myth, but that is my 2 cents.</div>