Can anyone explain what's going on here to me?

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thepedal
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Can anyone explain what's going on here to me?

Post by thepedal »

I have some tunes with six qsamos on one side and a bass one on the other side. I can play these for hours at a time sometimes without a problem then other times I will play for a little while and suddenly the qsamos are all using high percentages of cpu and sound has broken down to noise. Muting all of them then brings the sound back just about.

I'm not surprised that I might be able to stretch my laptop a bit with lots of synthesis, but what's strange is if I shutdown buzz and open the tune(s) up again it's still screwy. I can even disconnect the soundcard and reconnect it again without any improvement. However, if I reboot the computer I can play the tunes properly again. How can it be that windows 7 retains a memory of having had a problem playing some synths in a tune when it was previously running? Tunes that later play fine after a reboot. Is it setting some state on the soundcard, is it the usb bus cocking up, is there something which is lodged in the registry which might do with clearing?

I'm using the polac kernel streaming driver with a MOTU ultralite, latest buzz. I spent a few hours today using latencymon and some other tools to give buzz the best shot at as many resources as possible. Killing off networking completely yielded the best reward in terms of stable buzz. Even with this completely stripped-back windows 7 I'm still running into this problem from time to time. Would love any hints on how to debug what's going on. Can I increase the verbosity of messages in the debug console? Is there something like strace I can use to get behind buzz while it's spazzing out?
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xlorite
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Re: Can anyone explain what's going on here to me?

Post by xlorite »

why not ASIO?
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thepedal
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Re: Can anyone explain what's going on here to me?

Post by thepedal »

I've tried playing with asio and wasapi drivers but still get the best performance out of these polac kernel streaming drivers. Never understood why though. I would have thought wasapi would be the best right now.
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xlorite
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Re: Can anyone explain what's going on here to me?

Post by xlorite »

strange. tried latest asio4all? but i don't know if the type of drive is the problem here. i don't use qsamo
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thepedal
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Re: Can anyone explain what's going on here to me?

Post by thepedal »

Generally the qsamos are using ~10% of cpu. I can take a longish loop, play it for a while without making any changes to anything and see this periodically creep up to 20 or 25 %. At this point sound starts to deteriorate. What I don't understand is how a set of patterns can cause a certain amount of cpu use for, say four times repeated and then on the fifth time around some machine can suddenly be using double or more the cpu. It's as though some pattern/action causes a lot of processing even though that same thing hasn't been a problem for several plays.

I've played with asio/wasapi/polac drivers now and they are pretty much all the same.

I've got networking disabled, am running the smallest list of services on the machine and generally don't think this is being caused by something else grabbing resources. It's buzz-audiodriver-soundcard stuff. If anyone has any suggestions on how to thoroughly monitor a process on a windows machine I'd appreciate it. There must be tools to find out what a process is doing, or waiting on, out there. I work a lot with linux and don't have a huge amount of Windows knowledge these days but am looking for something like gdb which will let me get inside the process while it's running. My soundcard has firewire or usb2. Using usb right now. I suppose I should really test how much this happens with firewire to rule out some usb bus crap as well.
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tinga
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Re: Can anyone explain what's going on here to me?

Post by tinga »

Unlikely that, but release parameter can use a lot of cpu, polyphonie in Qsamo by default is 16, in the past i've experienced this, cause i like sound withe long release :oops: , and it costs ton of cpu.
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UNZ
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Re: Can anyone explain what's going on here to me?

Post by UNZ »

it might be a garbage collection issue, hard to explain those spikes otherwise
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