Over the last few days when using itunes there will be some severe crackling occurring in the audio whenever I load a webpage. At first I thought it was an issue with the soundcard driver so I uninstalled the drivers and re-installed them to see how it went. At first it seemed ok, but the crackle eventually made it’s way back.

I did a search on various sound card issues relating to crackle and other audio problems and came across the possibility that my DPC latency is going through the roof. I downloaded a handy piece of software called DPC Latency Checker. You run this in the background and see what the performance is like when doing various tasks.

Above I have included a screenshot of my reading at the time. Green is perfectly normal, yellow is acceptable and red is Bzzzt… crack… hiss land. It’s worth noting that loading applications will produce a red bar of a third of the size of the bars shown in the screenshot, this is not enough to affect audio performance though.

I went into Device Manager and tried disabling a few bits here and there and found out that it’s the onboard NIC that’s causing problems. All the time it was disabled my readings showed small green bars with one or two slightly larger yellow bars. At this point I’m not entirely sure what the problem is but I’m assuming it’s one of the following:

* The Realtek driver for my NIC has gone bad.
* I’ve recently switched out my normal router for a BT Home Hub due to some internet issues over the weekend.

I’ll try both of the above and keep you posted.