Alienware X51 Screen goes black when playing games

[Shivzy]

I have an Alienware x51 R1. It has a gtx 555 and I attempted to upgrade it to a cheap gtx 660. It worked fine for a few mins however when I started playing games my fps would rapidly drop and then my screen would go black. After about a minute my screen would enter rest mode but the pc is still running. Any Suggestions on what is wrong and how I can fix it?

 

[RARRAF]

well the system comes with a small PSU http://www.dell.com/support/article/uk/en/ukbsdt1/SLN296867/alienware-x51-r1-system-specifications?lang=EN
the only way you could fix it is with a better wattage PSU

 

[Shivzy]

well the system comes with a small PSU http://www.dell.com/support/article/uk/en/ukbsdt1/SLN296867/alienware-x51-r1-system-specifications?lang=EN
the only way you could fix it is with a better wattage PSU

I have a 330w PSU which I was advised would be fine by alienware

 

[King_V]

The GTX 660 actually has a slightly lower maximum power draw than the GTX 555. 140 vs 150w, based on the specs from the GeForce website. This, of course, assumes nothing's been tweaked by/for Dell, either lower or higher, for the GTX 555.

http://www.geforce.com/hardware/desktop-gpus/geforce-gtx-660/specifications
http://www.geforce.com/hardware/desktop-gpus/geforce-gtx-555-oem/specifications

Is the fan on the GTX 660 working appropriately? Speeding up as much as it should when temperatures build up? The symptoms kind of make me suspect there's thermal throttling happening.