Skein uses about 80% TDP on my GPUS.  I think Scrypt was at 100% when i pushed them.  Either way, its the middle of summer here, wont be running skein until winter, even then its a toss up.  

I always thought there was specialized hardware for Groestl, turns out, i was right.  I kind of forgot it was a Sha-3 candidate.  Its cool reading some of the academic white papers on Groestl.  

Looks like Skein is the only algo that doesnt require specialized hardware =\.