I have a 6770 in my prebuilt Dell XPS 8500 computer. This is OK for most games, but I'm looking to run Crysis when it comes out. I have looked at the 7870 and I have most of my questions answered but a few.
The computer only has a 460W power supply, and I ran my computers specs through numerous PSU calculators, and at max load on all components gave me a minimum PSU wattage of 410W and recommended of 450W. That being said, is it OK for me to upgrade?
Second, what do I actually have to do when replacing a graphics card? I know how to physically replace it, but what do I have to do about drivers, etc.?
capacitors do not age chronologically as most people think; heat ages them. heat is caused by inefficiency; a 75% PSU will supply 75 watts for every 100 watts it draws fomr the wall, the other 25% (or watts in this case) is "lost" in heat.
so therefore, better more efficient PSUs capacitors will last longer. keeping the idle above 20% and maximum under 80% is ideal and helps keeping the PSU from getting too hot.
(sorry about the lecture)
most non reference cards like what you are looking at, don't have too much of a difference in wattage. manufacturer raises the core speed without raising the voltages in most cases. a slight OC like that card will only need a slight more in power consumption. (~5 watts more)
when folks get cards and raise the voltage to help increase the core clock, then the power consumption can increase substantially 10%-40% more (thats percent not watts; a lot more)