Does x5650 consumes more than i7 920

[topmysteries5]

I had a crypto mining rig with Asrock H110 pro BTC motherboard + Pentium G4500 (2c 2t @ 3.5Ghz) + 8GB ddr4 + 120gb ssd.
When i was stress testing prime95 on this rig before installing any gpu, whole system power consumption was 39-41watts on full load as displayed on kill-a-watt meter. Idle was 23-25watts. PSU was HX1000i 80plus platinum.

If you still want more performance @ lower power consumption, then best cpu for you will be i7 8700T 6c 12t (2.4-4.0Ghz) @ 35w TDP. It scores 1050CB, which is much higher than 820CB of x5650.

 

[Shmee]

You are overthinking the whole power requirement thing. As long as you aren't overvolting a bunch, or putting in a graphics card which draws too much power, you should be fine with an X5650 or even higher Xeon. They generally run cooler and faster with +2 cores. Just get a decent Xeon, put it in, and there is no need to worry about voltages or power unless you really want OC, but then you should possibly upgrade PSU and CPU cooler.