Building a new gaming PC - Is all this compatible?
Fractal design 1000 Intel pentium G860 Radeon hd 5780 - I know my CPU may bottleneck this, but I can get one for an unbelievably cheap price (£85!) 550W XFX Pro Series ATX PSU with EasyRail™ Technology 4gb ram 500gb western digital HD GA-H61M-DS2 Motherboard
Yes, it's all compatible, but i rather get a new card like the 7850, which is better and for ~120£ and with two or three games free. Also the xfx 450W will do for the setup, it will shave some for the card.
Whether its compatible or not depends on a number of things you have not mentioned .
Your RAM should be a 2 x 2 gig kit rated for 1.5 volts or less I could guess and say its compatible but I prefer not to