http://extreme.outervision.com/psucalculatorlite.jsp

I already knew that the PSU I'm using for my computer is a little underpowered but thanks to this tool I can know exactly how much more I need.  I have a [url=http://videosean.gotgeeks.com/i/Ziggo5/2007-03-22_Ziggo5/images/dsc06680.jpg]300 watt[/url] cheap/spare PSU and finally reached it's limitations today trying to play FEAR and UT.  Fear will run for about 4 minutes before the power to my computer shuts down and UT for maybe 15 to 20 minutes before the PSU turns off.

According to the PSU calculator above I should have at least 430 watts for the crap I have in this machine LOL