I just got my 3570k yesterday and put everything together. After installing everything I download coretemp/realtemp and checked my idles. For some reason my core #0 is quite a bit higher than the rest.
package temp 34c
I did some load testing with prime and these were the max temps after an hour:
package temp 54c
Pretty much the same on load except for that rogue core#3. I thought it may just be a bad seating of my Hyper 212+ so I took it off and checked the paste(only a few hours after I had put it on). There were a few gaps in the heat pipes and part of the IHS didn't have paste on it. So I touched it up with a little more thermal paste and figured that I had fixed it. When I booted it up, I get the same behavior just a little cooler on both idle and load.
That's normal, yes. My 2500K has two rogue cores; one that's always a few degrees warmer than the others and one that's always a few degrees cooler. (For me it's Cores 0 (the cool one) and 1 (the "hot" one))