Did you get your system configured the way you wanted and then realize that you needed more power for your graphics cards? You could go the traditional route and get a bigger power supply. Or you could go in a new direction and get the BoosterX 3 from FSP.
This supplemental power supply fits in an unused 5.25" bay and delivers 150W to each of two 6 pin PCIe connectors. This takes a large portion of the load off of your regular PSU so it can use its power for your CPU and drives. You can also stack boosters for today's power hungry cards with multiple connectors or the Tri- and Quad- SLI configurations coming out.
Supplementary Power SupplyThe FSP Group BoosterX 3 FSP300-1E01 fits easily into an unoccupied 5.25" drive bay, providing additional 300W power to support your high-end multi-GPU graphic interface card power requirements.
NVIDIA SLI CertifiedThe FSP Group BoosterX 3 FSP300-1E01 power supply has gone through a series of rigorous NVIDIA SLI certification tests for maximum system stability when building NVIDIA SLI PCs.
Pros: If you've got a free 5.25" drive bay, an empty card slot and an unused 4 pin Molex power connector, this auxiliary PSU for you. The installation is a snap and you end up with 2 PCI Express power cables, each able to supply 150W to your video cards. I was considering buying a high end 850W PC Power & Cooling Supply to replace my existing 600W PSU, but this option is a lot cheaper. The card slot is just a dummy faceplate to let the AC power cord run neatly out the back of your case. The Molex connection allows the unit to turn on automatically, when you power up your machine.
Cons: The price is bit steep just to supply your video card(s), but if you're considering replacing your existing PSU with a new high end, high wattage replacement PSU, then the price is pretty good.
Overall Review: Since the motherboard PCI Express slots provide each video card with 45-50W anyway, the BoosterX 3's power rating is overkill, at least for many of today's cards. However, it's a good choice for the power-hungry 7950 GX/2. (143W under load) And you can install more than one BoosterX 3. Why, I don't know? ;-)