Am I Using all my Watts?

Not even close.

- Your Core i5-655k's TDP is 73 watts. That is its maximum power draw. (6 amps on the +12V).

- The GTX460 has a TDP of 160 watts, straight from the source at nVidia: http://www.nvidia.com/object/product-geforce-gtx-4... 13.5 amps on the +12V.

- The HDD draws a maximum of 40W during bootup. 20W max during seek. 3.5 amps on the +12V.

- Rest of your system (mobo, RAM, WiFi card, optical drive, fans) will draw less than 100 watts, tops. 8 amps on the +12V.

Total amps your system pulls when every component is using max power at the same time (which NEVER happens) is 31A on the +12V.

Your Antec PSU has 48 amps available on its +12V. You have enough power to spare on that PSU to add another GTX460 to run SLI if you want.

Not sure what you mean when you say your "fan speed controller stopped working." If it is one of those "smart" ones that will automatically speed up the fans in response to heat and you hear your fans going loud, that is normal behavior. It's doing its job getting the heat out of your case.

If you mean the fans STOP spinning, then you got issues with the fan controller. I would try another fan controller.

Based on the list of components I'd say the motherboard is at fault. OCing can great for learning purposes but really any extra power gained will very quicky harm other components. You have to realize the CPU, Mem, and motherboard are set to operate within specific standards. Anything beyond is not good for a production environment. Nice build though.

I doubt you demanded too much from your power supply. When you do that you'll start to see random crashes, shut downs and graphics card failure. In some cases the PSU will die (seen it all!)

The fan speed controller may appear not to be working because of the extra strain on your system (it's working harder to keep it cool). It may even be a safety feature of the motherboard / over-clocking software if you are over-clocking.

I think you'll be fine adding a blu-ray drive and keeping your system over-clocked.

Dave

Edit, just to add,

Your Graphics card's power consumption at load is 270W ( http://www.bit-tech.net/hardware/graphics/2010/07/... ). You may add 20W as it over clocked.

Your processor is rated at 73W

Everything else is not likely to come over 100W.

Total is considerably less than 500W.

You have a 620W PSU, so you are far from killing it.