I have a Thermaltake "SMART M1200W" PSU. I currently have 3 MSI 7950's TWIN FROZR 3GD5/OC and would like to add a 4th. However I'm not sure how to make that work with the power supply that I have. It only came with 6 PCI-E, and I have used all six of those for the GPU's that I have. On the back of the CPU their are only 3 plug ins that fit that particular cord and they are now all used. There are other plug in's on the back but none that will fit another cord like that. Any advice on how to be able to add a 4th GPU to my rig without needing to buy another PSU?