Ok so my problem is after leaving my computer on for extended periods of time or overnight when I come back to it, it behaves very lagy. For instance if I try to play music or watch a movie, any sort of audio is filled with pops and stutters and the only way to fix things is to restart. My sound is routed via optical cable to an audioengine D1 DAC into my speakers. This DAC was purchased after the sound crackling in an attempt to fix it but it has offered no change. The next thing is when I play games if the computer has been on for a while and I go to play a game the frame rate will be very unstable and I notice quite a bit of choppiness, again restarting will alleviate this for a while. Windows also experiences this lag they become choppy and jerky when moved around and the system seems less responsive, again restarting alleviates this for a while.
At first I thought maybe something is taking up all my ram caused by some memory leak but when I open task manager only about 20-30 percent or so is being used. I also do have another problem that happens very rarely Ill be playing a game talking on Skype and all of a sudden everything freezes a stuttering noise comes out just as if its about to bluescreen but instead the screen mouse and keyboard become completely unresponsive so I cant click anything or access task manager and the screen remains stuck on the last image. The strange thing about this is the sound continues to work and I can still talk on Skype and the people im on Skype with can still hear me but other than that im completely frozen and am forced to hold the power button to power down and turn back on (this problem hasn't occurred in over a month now).
I am running windows 8 and so far I have run memtest for 20 hours and it has come back with no errors, I also have done a clean re install of windows installing nothing but the bare drivers and a game which offered no solution and the problem still persists (system wide lag, very unstable frame rate in games and crackling in all audio. Restarting cures all of these problems but after a few hours of use they return and a restart is required). Any solutions to this would be helpful thanks.
CPU: Intel Core I7 2600k
Mobo: Asus Maximus IV Extreme
Ram: 8 gigs Corsair Vengence 1600Mhz
Samsung 830 Series SSD 256GB
Western Digital Caviar Black 2TB
Graphics: Asus 680GTX TOP
PSU: Corsair AX750
Case: Corsair Obsidian 800D
CPU Cooler: Corsair H100i
OS: Windows 8 Pro 64bit
Monitor 1: Samsung series 9 S27B970D
Monitor 2: Asus VG248QE