Those of you who GPU mine X11 coins, did you notice that CPU is used 25% ?
I tried it, mining works great with my 7950 card and I get 1,6MH/s (darkcoin) but CPU is used 25% constantly.
This does not allow my CPU to go to power saving mode and in the end, although my GPU runs cooler, I think I end up using a lot more power.
Did you notice the same?
I'm mining X11 Hiro on the PC I'm typing this to you and my cpu is running at 11% and I'm watching an episode of Fringe so I think it must depend on your cpu. I'm going to mine it on my rig at work when I go in and that's a different cpu to home to I'll see what that uses.
[Edit]
So my home CPU (FX 8320) uses 11% on X11. (1xR9 280x)
My work PC uses 28% (Athlon x2 250 with (1xR9 280x)
My rig (Sempron X2 245) uses 26% (2xR9 280x)
So CPU usage is up on X11, but it's not a lot and it'll still be less power than the GPU not running X11 algorithm so it's nothing to worry about.
It's also awesome seeing a hashrate of 8mh/s+ with only 4x R9 280x