Hello I'm new here in this site, also advance sorry for my bad English
anyway here's my problem:
I bought an GTX 660 non-Ti a month ago
every time I play for about 20-30 mins, my games crash, I don't see any artifacts in the game it's just crashing
and after some crash, I can't launch google chrome, I got an error of APPCRASH
I also notice that sometimes, when the GPU hit around 60c and above, the crashing occurs
also I have a Rocketdock running in my desktop, whenever I browse rocketdock, I have a strange glitches in the icons
Which drivers are you using? If you're using the latest drivers, revert back to one where you didn't have any issues.
Secondly, I don't think your PSU would be the cause of this issue. However, with generic no-name PSU's you can't trust them to even provide the rated wattage. I would highly recommend swapping out out ASAP.
I would try something like OCCT GPU test, 3D Vantage, FurMark or Unigine. Really anything that will warm the card up and see if it crashes. OCCT GPU test or Furmark would be great as they run windowed by default. Then you can keep an eye on any monitoring software as the card warms up. Also with either of these two, it should warm the GPU up really quickly. If heat/GPU quality is really the issue, it should crash very quickly with either of these two tests. Even though 60 degrees isn't that warm especially for nVidia GPU's, I've seen cards start artifact and crash as similar temps.