PC Notebook DPC Latecny problems

Rob Spence

Rob Spence

Senior
Jan 11, 2011
897
4
18
Boston Metro North West
www.lynxaudioservices.com
I am trying to stream some audio from my laptop pc running Vista.
I am using a ASIO driver.
I get a glitch in the audio every 12-14 seconds or so. At that time I get a spike in DPC latency which measure with a cool tool ( http://www.thesycon.de/deu/latency_check.shtml ).

The latency spikes every 13 seconds or so and is twice each 3rd period or about 35 seconds.

I have been struggling with disabling devices, removing stuff I don't need, all sorts of things and nothing has changed it. I even spent 2 days with the windows performance analyser to no avail.

Anyone have any suggestions (besides get a MAC - I plan to but for now...)?
 
Re: PC Notebook DPC Latecny problems

Rob,
On a couple occasions I have seen this due to I/O conflicts with onboard chipsets such as the wireless lan. Try completely disabling the wireless (ie in device manager). Also, what ASIO driver are you using? You might try ASIO4All which is a generic driver, it might work or at least help you further diagnose.

What is your audio device - USB, Firewire? If firewire it could be a matter of the driver not liking your firewire chipset.

Best of luck, sometimes these sorts of things can be tricky to diagnose.
 
Re: PC Notebook DPC Latecny problems

I would try the latest drivers, then older versions of related drivers, etc. You can also set your PC for background services:

right click on My Computer -> Properties. Click on Advanced tab, then Performance Settings. Set Visual Effects to "adjust for best performance". On Advanced tab, maybe experiement with "Adjust for best performance of Background services".

Disclaimer - I'm on Windows 7 - YMMV on Vista for what those buttons are called, but they may be worth a try.

May also want to run the msinfo32 tool (in older versions called winmsd) - this shows some stuff that launches on startup that is hard to see.

One other suggestion (other than getting a Mac :) would be to disable power management settings, both in Windows, and in the BIOS, if any.
 
Re: PC Notebook DPC Latecny problems

Rob, I had problems with Smaart on my Lenovo R500, and the Tascam US122MkII i/o box drivers and the M-Audio Mobile Pre USB. I found them both writing to disc about every 10 seconds, freezing the screen display for a second or 2... both with ASIO drivers. I *increased* the driver latency and the problems went away.

Have fun, good luck.

Tim Mc
 
Re: PC Notebook DPC Latecny problems

Jeff Babcock said:
Rob,
On a couple occasions I have seen this due to I/O conflicts with onboard chipsets such as the wireless lan. Try completely disabling the wireless (ie in device manager). Also, what ASIO driver are you using? You might try ASIO4All which is a generic driver, it might work or at least help you further diagnose.

What is your audio device - USB, Firewire? If firewire it could be a matter of the driver not liking your firewire chipset.

Best of luck, sometimes these sorts of things can be tricky to diagnose.
Click to expand...

I am using the Dante Virtual Sound Card with an American Audio ASIO driver. I suspect the ASIO driver too and would like to know any other suggested ones to try (other than ASIO4All - which I intend to try).
 
Re: PC Notebook DPC Latecny problems

What's the declared latency that the driver or the program you're using? If it's a small figure ie in the low tens then as Tim says try incresing it either in the program or directly on the driver's settings page. In my system using a Roland driver Reaper is glitch fre at 40 samples/ 40ms this setting works for the roland kiit up to 24 channels but for an older Presonus driver it had to be opened out to about 120 to get smooth playback on less than 16 channels. G
 
Re: PC Notebook DPC Latecny problems

gordon mcgregor said:
What's the declared latency that the driver or the program you're using? If it's a small figure ie in the low tens then as Tim says try incresing it either in the program or directly on the driver's settings page. In my system using a Roland driver Reaper is glitch fre at 40 samples/ 40ms this setting works for the roland kiit up to 24 channels but for an older Presonus driver it had to be opened out to about 120 to get smooth playback on less than 16 channels. G
Click to expand...
Hmm, I use Reaper too. I will check on the declared latency. I think it is 8 or something like that.
 
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