I am purchasing a GTX 480, but I'm not sure if my Corsair HX520W is capable of supporting it. I have seen the benchmarks that show that this power supply can be loaded up to 600W, but the 12V rail is only 18A, but there are 3 of them. I am pretty sure that these rails don't add, but I would rather not purchase a new power supply, but will if I must. I will be doing some CUDA programming on this machine, as well as gaming. If it's important the system will be running:
5 hard drives (all SATA2, one Raptor)
1 SATA optical drive
A Core 2 Duo E7600 CPU
8GB of DDR2 RAM
It would probably be pushing the limits - It would have enough power for the system you just described - however, running it at its limits the majority of the time would not only degrade its lifespan, but it would have lower efficiency and the fan speed would be much higher.
Therefore I suggest a new power supply, the XFX Black Edition 750W 80+ Silver certified PSU for $119.99, $99.99 after rebate:
Thank you for the responses. I was fairly sure I was going to have to replace the power supply, and this confirms it. Thanks for helping me not have to wait for a new power supply once the new graphics card arrives.