|If your system is fairly new, the power supply should have a 6-pin PCIe plug available to connect to the card. If not, you MUST use the adapter cable. If he just gave you the card, how did you manage to lose the adapter so fast? And you need to look at your power supply specs, not just the wattage, but the amperage. Seeing as how the card requires the 6-pin plug, it means it consumes more than 75W (approx 6A on the +12v) under full load.|
The AMD 760G chipset has the Radeon HD 3000 integrated. The 8600GTS is considerably better. But you need to ask yourself if you're actually going to take advantange of it or if you're only upgrading because you can.