Quote from: PopeSeanV on April 25, 2013, 03:33:29 AM

Ah well then, don't bother with the CPU. It will only waste electricity and shorten the lifetime of your equipment.

I completely agree with this. Shortening the lifespan of your CPU is not really worth the benefits of those 4-5Mhs.
I also have a i5-2500k and would never think of using it for mining, but not just for this reason.
If you attempt to mine with both, using only 3 cores of the CPU as to not affect your GPU mining ability, then if for some reason you end up using the CPU heavily, the GPU will bog down and you will lose GPU hashing ability. Usually by about 75%.

So if you end up trying to use both and say, have Windows Defender on autoscan at 3am, you'll end up running a slow scan and lose GPU for hours and hours.

Try it out. I learned the hard way. And I'll never do that again.. Sad