Computer starts lagging after left idle

[junkai21]

Hi!!! When watching youtube or movies, regardless of player, the image on screen will start to lag. When u press any key like "Ctrl" or simply move ur mouse pointer, it will be back to normal. After say... 10 sec it will start lagging again. Anyone experience this before?

I've tried:
Setting power settings to "High Performance"

 

[jtjt00]

Try these:
1. Memtest86
2. HDTune full normal scan for bad sectors.

 

[hlots123]

http://forums.hardwarezone.com.sg/hardware-clinic-2/weird-furmark-lag-motherboard-gfx-4524314.html
Windforce 7950 fps drop while idle [Solved] - FPS - Graphics & Displays

any unknown processes...?