Getting gratuitous amounts of soft page faults when loading games and watching flash video
Solution 1:
After reviewing the information here and discovering that the issue is that he's page faulting quite a bit, I'm going to add some more possibilities that I'd look into, here.
If these are soft page faults, and you're getting a lot of them, my guess is that the memory accesses that are causing these faults are requests for texture resources. The graphics card has some amount of on-board memory to speed up texture fetch requests, but for some reason, it may be that the drivers aren't caching enough of the texture in the on-board memory, or it isn't caching any of it at all. I am not familiar with nVidia's graphics driver settings very well (I've been running ATI cards primarily for the past 4 years) so I am not sure if a driver setting, overclocking setting, or even a BIOS setting would be to blame for such a state. However, I would look into this to see if it may be the source of the problems.
Also, as a note, I logged page faults/sec, as you did, for Portal 2, and found barely any. Of course, my system is using 2 Radeon HD 6970s in Crossfire, however, your graphics card should certainly be capable of handling Portal 2 without pagefaulting like that. If all is operating properly, I'd expect you would see a similar image to this:
If we want to rule out that the graphics card is the culprit (or the graphics hardware as it is being used by the computer, anyway), I'd recommend disabling Aero and seeing what happens when you are idling at the desktop. If the number of page faults decreases, then my hunch that it is graphics related is probably correct. If not, then it may be elsewhere.