Power supply is 500w sorryWhat is the make/model of that power supply? Just the wattage is not enough to know if needs replaced too. Personally, I wouldn't invest any money into such an old system. Why are you looking to get a graphcis card?
Power supply is 500w sorry
gt610 ??No PCIe power connectors and a 288W 12V rail that is already powering the 65W CPU and the rest of the system.
75W GPU is possible, but finding something that will operate in such an old machine, hmm. What OS are you running?
How much are you wanting to spend? For the price of GPUs you can plug into that you may be better off with pretty much any off the shelf desktop/laptop with integrated graphics.
bottleneck?While that would probably work and there is a relatively recent driver for Windows 7 it is very limited GPU. If all you need is a display output and it is cheap enough, sure. If you want to do something like light gaming, you want the GT630 or GT730.