Is a graphics card power cable needed because not all graphics cards come with one? And if it isn't needed, what is the benefit?
Graphics cards get their power from the computer slot into which they are plugged. I've never heard of needing an external power source.
not all graphic cards need them. But lately the graphic cards are using up quite a bit of power, especially the high-end ones. So if the graphic card has a pci-e power connector. Chances are it will need it. Otherwise your computer might show graphics are there will be error when trying to play games or other graphic intense applications. The same thing is happening to graphic cards, that happen to processor a few years ago. Not that long ago processors could just be powered by the energy coming from the bus line on the motherboard, but that is not true anymore and now we use 4-pin or the new 8 pin axillary power for the processor.
The more powerful graphics cards require the 6-pin power connector to a PCI-E slot. The benefits of NOT requiring one are: 1) The card uses less power, which might save the expense of having to upgrade the power supply. 2) The card works with power supplies that don't have the PCI-E cable, without having to buy an adapter. The best card which doesn't need a power cable is the ATI Radeon 4670. The card models above that (like the GeForce 9800GT, Radeon 4830 etc) all require the cable.
