I'm having some weird issues with the wallet software

I have an Intel I7 6700K and for Monero for instance I get 300 H/s with 4 cores with the CPU at 50% usage and 45º C. For Credits, with 4 cores (setgenerate true 4) I get 20 kH/s with average 50% usage but like 75º C temps and I tryed using all 8 cores and my procesor reached 90º!!
Anyone having the same problems?