My computer crashes when I play Civ 5 on medium settings (DirectX 11) at my screen's native resolution (1600*1050). I've tried adjusting many video settings and I've only been able to play it without crashing at low settings, reduced resolution (1440*900), DirectX 9, and I also set my computer's power settings to Power Saver. But that makes the game rather laggy, especially late game.
Here are some specs:
Intel Core 2 Quad Q9550
NVIDIA GeForce GTX 550 Ti
Your PSU looks like a questionable unit but it's difficult to determine if it is the real issue without substituting a known good, capable PSU.
I'd try re-seating the RAM DIMMs and video card then run Memtest86+ first to see if you have RAM issues. If that's Ok then i'd try stress testing your PC with OCCT. If that's good then try Prime 95 for 24 hours.
Your PSU is a fecal piece of Chinese junk. It may be good for half its label, and that not cleanly. A quality 450W-500W PSU would be sufficient for you; something like an Antec Earthwatts or HCG, or Corsair Builder.
While you could also have driver problems, dealing with unstable power is an exercise in futility.
You need to open up your PC case and examine the numbers on the PSU. Specifically how much voltage it can handle on the 12v1 and 12v2 rails, having a lot of watts isn't helpful for a modern-day GPU if the 12v rail isn't up to snuff.
This is the best advice I can give you, remember when you buy a new PSU to change the Power Settings on Windows back to Balanced, having it at Low Power severely handicaps the CPU and GPU.
If your PSU is of bad quality, generally speaking you should be getting some spark activity inside your PC. Worst-case scenario is that it takes down another PC component with it. Since your PC is shutting itself down I would imagine its of decent quality and is trying to tell you it doesn't have enough juice. Since you exceed the watts requirement for the 560ti, I'm still going to blame the lack of juice on the 12v rail as the culprit. Don't keep pushing the PSU to turn itself off since it's of questionable quality.
I would think that buying a 650w psu for $25 is not a good thing , sure its cheap but as they say you get what you pay for. If you can afford it I would get a 650w psu from some other place besides e-bay or even if you did go back to e-bay get a name brand. I do a lot of shopping at Newegg and they do have good prices;
Also how much ram do you have? What is you OS , 32bit or 64bit , Vista or 7 or XP?
I'm running 64bit Windows 7, and I've got 6gb DDR2-800 RAM.
I'm new to building computers, and I'm trying to learn the various ins and outs of selecting parts. I didn't select the PSU in my computer, and I had a hunch that that was the problem. You guys confirmed it and I'm currently researching PSUs.
Corrective action - Remove PSU and use as it was intended, your choice (A) Boat anchor, (B) Door stop, (C) deep six it and let the baby crabs have a home - OPPS not enviorntally good idea. Even if not the problem it could lead to R&R entire compute (R&R is not rest & relaxation).
After replacing and still have problems start looking at drives, temps and voltages.
Use Prime 95 to test stability (CPU and memory), CPU temps and PSU voltages - primarily the +5 and +12 V rails. Next run Furmark in a window while monitoring GPU temps and again monitor your +12 V rail. Mins +5 v => 4.75 V and +12 V => 11.4 although I use 11.6 as a Min when under load.
Just to reiterate what everyone else here has said, your PSU is not good and even if it is not at complete fault here, you should get a quality unit ASAP. Cheap units like this can cause all sorts of problems, and yes, even catching on fire or frying every component in your build instantly with 1 good power surge. A decent gaming build always, always, always with any question starts with a quality PSU. There is no other choice in this matter.