Lag-spikes when approaching max download rate

[Bagarn]

Hi,

Im experiencing a strange problem when using uTorrent v1.8.1. When the download rate is starting to reach max, 1mb/s in my case, I constantly get small lag-spikes. The cursor tends to lag and when listening to music it also lags. Its just small spikes occuring every 10 seconds or so, but its really irritating. It only occurs when the download rate is high. No problem at all with the uploadspeed or when downloading at 80% of the max rate.

At first I was sure it had to do with my harddrives being too old, but I recently replaced them and the problem still remains. Currently running windows on a 250gb 16mb cache SATA drive and using a 500gb one to store my downloaded data on. Other than that Im using a 2.2 Ghz AMD cpu and 2gb RAM. I dont get any strange CPU usage during the lags. uTorrent process maybe triggers up to 10-15% of CPU, no more than that.

I've read a lot of other threads here on the forum discribing similar problems as mine, however most of them differs in some way. I've tried changing different options under Preferences -> Advanced -> Disk Cache but no luck there.

So...anyone got a clue what my problem might be?

/N

[Ultima]

Hm. What security software are you using?

[Bagarn]

Norton Internet Security v16.1.0.33

I upgraded to it about a week ago, before that I was using another version of Norton 360.

[Ultima]

Just for the sake of testing (if you don't mind -- please don't? XD), can you uninstall Norton and run its removal tool? Does the problem persist after that? It may well be that Norton's scanner is lagging things (I don't know for sure, but it's the only hunch I have to run on ATM).