Which is better

The HD4650 is better.

4650 is stronger, try to get a DDR3 version of it as that performs a fair bit better.

Also, unless you find a ddr3 version that's under $65, you might as well get an HD5570, which performs like an HD4670 with much lower power consumption.

Yes i would agree that if its not at the right price then look at a low ens 5 series card.

Mactronix