Can I save energy used on my power supply ( HX850W )

Hi,

 

I used this 850W power supply because I wanted to build a gaming pc with high end graphic cards initially ( I had 2 GTX465 in SLI )

 

However, I don't want to use this machine for gaming anymore. I plan to install a very low profile graphic card which only use very little energy.

My purpose is to save my electricity bill, since 850W is a lot considering I use pc 8 hours a day.

 

My question is: Can I really save energy by removing pc parts which consume lots of wattage? or my power supply will always consume whole 850W? I think there should be something like smart setting which can detect how much wattage pc has now and lower the total wattage accordingly, but I don't know where I can find related information to confirm this.

Yes you will consume less power. The PSU itself doesn't consume much power at all. You were likely never drawing 850 watts, probably something in the 600-700 range and even then only when those GPUs were fully loaded. Not only will you consume less power but the PSU is much more efficient under low loads so you will waste less energy as useless heat.

I think there should be something like smart setting which can detect how much wattage pc has now and lower the total wattage accordingly, but I don't know where I can find related information to confirm this.

All PSU's do this by them selves. They will only supply as much power as what the system demands. So as G50EED stated even when gaming you were probably never using the whole 850watts. And at the most a couple of hundred at idle.