PSU Wattage Calculator
You would never really get close to 1200w, unless you had like millions of cards, HDD's etc.
Still, i think it's just bragging rights!
"Hahaha, my PSU is bigger than yours"
That's correct. I know two people who overloaded a high end 1000W power supply (they both have the Corsair HX1000). They has the following specs.
Person #1 (Mutt Slayer on EVGA forums)
Intel Core i7 920 D0 (tried for 4.6 ghz, PSU couldn't do it)
EVGA GTX 295 Plus and EVGA GTX 295 Quad-SLI (not sure of clock speeds)
2x Western Digital 150 GB VelociRaptors Raid 0
Seagate Barracuda 320 GB
6 GB RAM (3 x 2 GB Corsair Dominator DDR3 1866, 9-9-9-24)
I'm actually surprised he overloaded the HX1000, which has 80A continuous on the +12v rails (960W). He keeps his CPU @ 4.41 ghz for the time being, until he gets a new PSU. The next person also overloaded the HX1000, but this one makes a lot more sense.
Person #2 (Socio-PC on EVGA forums)
EVGA X58 Classified (it can take dual 8-pin CPU connectors for 300W of power just for the CPU)
Intel Core i7 920 @ ~4.5 ghz
EVGA GTX 295 Quad-SLI (unsure of clock speeds)
EVGA GTX 275 PhysX Processor (unsure of clock speeds)
2x WD RaptorX 74 GB RAID 0
12 GB RAM (G.SKILL DDR3 unknown speed, CL8)
He upgraded to a COOLER MASTER Real Power Pro 1250W which has six +12v rails and 93.75A continuous on them, no more issues.