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I'm getting DPC latency spikes every 60 seconds related to Dell 1515 (atheros) WLAN. If you turn off the wireless card, the spikes go away. If you disable wireless autodiscovery, they go away. I've seen a blog post with a script to disable autodiscovery while you are connected, then you have to run anotehr script to eable autodiscovery again when you disconnect. That didn't work for me, and I really want a real fix, not a workaround.

These spikes often cause network dropouts, sound dropouts or video freezes.


I am running Windows Server 2008 on this laptop. Also tried dualbooting with Windows 7 (default drivers) - same issue.

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I'm assuming that your reference to DPC implies this is on a Windows platform.

The page documenting Thesycon's DPC Latency Checker Tool has the following good advice when the driver responsible for DPC latency spikes has been identified:

When you have identified the device driver which is responsible for the drop-outs consult the device vendor's Web site or customer support to find an update for this driver. If this is not possible you may decide to keep the concerned device disabled while you are using streaming applications.

Clearly, if you must receive the stream via the wireless driver then disabling it is not possible though I'm not clear from your question whether you can just disable autodiscovery and still successfully use the card to receive the stream. Whilst this is a workround it may be the best compromise until the driver is fixed, if it can be. As the Thesycon page points out:

Processing of streaming data in real-time is a very challenging task for Windows based applications and device drivers. This is because by design Windows is not a real-time operating system. There is no guarantee that certain (periodic) actions can be executed in a timely manner. ...

If you have not already looked at Thesycon's DPC Latency Checker Tool and your project is on one of its supported platforms and is non-commercial then you consider using it for free to confirm your conclusions. Details of the tool and next steps are in the page hyperlinked above.

One final, obvious, suggestion is to relieve the PC of other work by not running unnecessary processes and ensuring sufficient free RAM may help.

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