Motherboard asus p8h61 + ubuntu 11.04 - trouble

[GrecPetroff]

I have Motherboard asus p8h61
CPU - Intel core i5 2400
Video - Asus ENGTS250
I have trouble with network and videoplayers. System(Ubuntu) after 30-40 minutes start to slow down, network(Download) from 80 Mbps became 3-4 Mbps, and movie's images slow down too.
I tried Ubuntu 11.04(x64 and x86),Ubuntu Mint 11, Kubuntu 11.04, Mint 9 Rosinka. Everywhere this problems.
May be trouble in hardware? Socket/Chipset/Drivers?

[bronxkds]

Hi,

I have this issue too, do you solve it? I use Ubuntu since 6.06 and I never see this. Network card is a typical Realtek 8111E Gigabit.

Thanks

[GrecPetroff]

Resolved. I changed motherboard. Use http://openbenchmarking.org/ and find something else. Asus p8h61 - is terrible..(