I'm currently in the market for a new graphics card (currently have an ATI Radeon 4850) in order to play some of the latest games on a decent setting (battlefield, GTAIV, SimCity), but I'm limited to both my current 350W PSU, along with a fairly small budget of £100.
My specs are:
Intel Core i7 Processor 920 (2.66GHz, 8MB cache, 4.8GT/sec)
6GB DDR3 Ram
512mb ATI Radeon 4850 graphics card
Delta Electronics PSU (350W Output, model#DPS-360FBA)
750GB Hard Drive
If people need any more details please ask, I'm sincerely grateful for any responses, thanks.
Your pushing that PSU about as hard as you can already. If i were you I would upgrade the PSU, you can get a gold level 550w seasonic for about 100 bucks (in aus, cheaper in America i assume). PSU's gradually degrade over time, so you may eventually run into problems even if you change nothing. If you really dont have the money, A 7770 would be a safe upgrade, you may even be able to get away with a 7850. 7770 would be a small upgrade and a 7850 a rather large one in terms of performance.
If you have a crossfire board. A new power supply but it would have to be at least two 20 amp rails or a single 40 amp rail or more. 550 to 700 watts depending on the model. A 750 watt antec, corsair or ocz or other trusted brand would be ideal.
And a used hd-4850 card. they are almost worthless today so a used one should be dirt cheap or about the price of a new hd-6570 or less.
Crossfire hd-4850's actually do well, but they are power hogs.
This power supply should be ok with a pair of hd-7870's or a pair of 4850's.
If you can find a used 4850 card locally for a reasonable price, this might keep you within your original budget.
(only if your board has two pcie-16 slots on it and can run crossfire)
One of the biggest (and most prevalent) mistakes people make is over working their PSU. You are the poster boy. I recommend you replace your current PSU with the highest wattage QUALITY PSU you can afford. You're wasting your money to do other. Replacing a PSU is a no brainer. Four screws and a bunch of connectors.