Power savings; Disable unused threads on Xeon, and remove unused RAM?


Nov 19, 2010
Hi all,
I have a Xeon E5 2650 V2 (10 core, 20 threads), and a V4 (12 cores, 24 threads) system. Both running Windows 10 home 64bit.

They were part of a server system before, but now are doing bitcoin mining and folding.
Actually, only the graphics cards are folding. The CPUs aren't very efficient, so they're just feeding the graphics cards.

I want to optimize my system for lower power consumption, as each runs at about 400-500Watt, 24/7; without losing too much performance.
Each nVidia graphics card uses 1 full thread on my system.

In one system I use up to 4 graphics cards,
In the other I use up to 7.

In Windows, I can disable cores in msconfig.
Because of the nature of the program, I can not assign affinity to the program, as every 20 so many minutes to a few hours, it changes PID, and thus affinity will be reset.

So I'm left with either setting the first system to 5 cores, or 8? (4 graphics cards, plus 1 core for system functions)
And the second to 8 or 14 cores?

The 8 or 14 cores, to allow each graphics card thread to use their unique core, rather than using a core, and it's hyperthread, allowing for more better cache throughput (one process using the same core)

Or would it be best to leave the system running on all cores, switching around as it sees fit; enabling and disabling cores at random?

I think I can save some power disabling at least half the cores, no?

Second is, I was thinking of pulling some of the ram sticks. It has 4x 4GB of RAM. I probably only use 3GB max. If anything I could use 2x4GB, and save power on the other 2 RAM sticks just idling by.
Is it a feasible move?

RAM sticks use very little power. You could pull 2 sticks (8GB sounds like plenty for your application), but the power savings would probably be in the 3-5 W range ... could be less.

As far as the CPU, I think you would get greater power savings from underclocking/undervolting your CPU, though, from what I understand about those applications, they don't work the CPU very hard so it probably is using less power than you think.

If you are really curious about this, get a Kill A Watt and test it out.