FFXIV Freezing and RESTARTING PC?

[Raist]

500W PSU may not be strong enough with how XIV is hammering your system. It's not optimized very well, so it may be causing your system to stress that PSU more than your other games. A GTX 660 itself recommends a 450W PSU as a minimum. Add in your CPU, number of memory sticks, drives, fans, peripherals... and you start to see why that recommendation shoots up over the card's 140W rating. It becomes even more important if you are overclocking something or ramping up fan speeds and such to improve cooling. At the very least, you may need a 600 or 650 watt certified 80+ design (noncertified models may only provide 60% of their listed rating under harsher conditions or as they age, while a certified has been tested to maintain a minimum of 80% of it's rating).

There are a lot of calculators out there to help you determine what you need. Here is one from Corsair:
http://www.corsair.com/en-ca/psu-finder