I have a 1,000W Gold Silent Pro Cooler Master PSU.
In my rig I have:
Core i7 W3520 overclocked to 4ghz
3x 2GB DDR3 RAM
X58 Classified EVGA mobo
3x 2TB WD Green Hard drives
2x OCZ Vertex SSDs
1x Bluray rdrive
1x Swiftech M660 pump
8x 120mm fans
Is there any chance I can run a 6990 and a 4870x2 on this single PSU? Or am I going to blow the whole thing up?
Cutting it close or just over the designed capacity, your PSU will likely handle it, but it won't be good for the operating lifespan and your efficiency will be below the best the PSU can do.
I ran a 4870x2 and the system draw was in the 400+ range, sorry don't have an exact figure because it was almost 2 years back since I measured that.
A 6990 with two GPU had been measured to draw as much as 439W (card alone) in performance mode so that's 940W + whatever is needed for your other stuff.
Should consider just getting a relatively cheap but efficient FSP 500W to take up the 4870x2 load.