My PC is having a problem where it can't do more than one task at a time. Doing so causes both graphic and audio glitches, as well as visible system slow down. For example, if I'm watching a video (netflix, off a hard drive, anywhere), and I'm trying to move a large file (even to a different hard drive), the video will lag (both sound and video). If I'm playing a game, and my internet browser is open to any page that autorefreshes (facebook, gmail, etc), the game will lag (again, audio and video drops, generally poor performance). If I'm playing a game that loads constantly (like Assassin's Creed) it's pretty much unplayable. I get horrible lag anytime the game has to load. If a game uses a video to hide a load screen (the opening of SWToR, ME2) the video skips.
Now, if I'm only doing one thing, like just playing ME2, just playing ToR, just watching a video, it's fine. Only when it loads in game, or tries to multitask do I see a performance drop. This happens all the time, not just under extreme load, or when the computer has been on for a while.
My rig is a AMD 6000+ (dual core, 3.0 I think), 4 gb ram, geforce 9800 GT, asus m3n78-vm, Sound Blaster x-fi xtreme Audio, Corsair 750 watt modular (total overkill, but it was a gift). It's about 4 years old, but it still makes rec specs on most everything, so I'd like to get a little more life out of this baby.
I think it's not the graphics or the audio card. If that is the case, I would see graphic or audio problems seperate from each other. If it was harddrive or ram failure, I'd have computer crashes, curropted data, etc. Since this problem seems to effect everything, I'm pretty convinced it's the Mobo, but I would love a second opinion.