Hd movie lag

[RunningRabbits]

Hello everyone I have a problem with hd video play where while playing a hd movies the playback will drop 4-5 fps for 30 seconds and it is throughout the whole movie. Any ideas ?

Specs:
Phenom 960t X6 @4.2ghz
Gtx 570
8gb RAM
650w PSU

I KNOW my system is COMPLETELY capable of playing hd movies so what's the problem?

 

[Maziar]

Do you have the latest VGA drivers installed ?
Also,have you tried any games on your system? If so,how was the performance ?

 

[RunningRabbits]

Yes I have many games such as skyrim, crysis 2, gta4, dirt 3, black ops 2 and all of my games I run at the max settings and they are all smooth @1920x1600 resolution and my graphics drivers are 310 I believe.