Experiencing almost random massive slowdowns
With an 8400M GS card, I'm experiencing extreme slowdowns quite often. I'm currently on the 256.35 driver, but this has happened with past drivers as well (at least from 180.x+).
When I start the laptop, at first a given game will run quite smoothly (recently testing with HoN). After a time, which seems random, the game will suddenly grind to an almost complete halt ~ 3fps. This can take hours, sometimes spanning exits from the game and its subsequent future start. Once the slowdown occurs, it stays like this indefinitely. Sometimes, but not always, a restart of X seems to fix the problem, and on rare occasions, even switching to a VT and then back to X seems to fix it, at least temporarily.