Ah OK, that sounds more like a reasonable range. Was it Sandy Bridge (or was it Ivy Bridge) that Intel introduced the dodgy IHS compounds that made it run hotter?
I'm just comparing based on TDP, my 1st-gen i7 is rated at 130w TDP at stock, as is your 3rd-gen i7 3930k. Mine's not really stable above 4Ghz at all, at least not on air cooling, but at 3.8Ghz - 35% overclock above stock turbo, it gets to about 65'c core on air. Yours is only a 21% overclock above max turbo but still nearly a Ghz higher than mine. It's hard to say which would be taking more power, mine's got a bigger overclock but yours is running faster overall and on higher voltage, yet mine's on older, bigger process (45nm) so yours is a lot more efficient.
Low to mid-30's under load is pretty decent, 45'c is OK I guess - depending on waterblock and IHS performance. It's the 65'c you mentioned earlier that seemed a lot higher than it should be, given my CPU does that on a standard air cooling. Not harmful by any means, but when you consider the tiny cooler on the right of
this image keeps a 3.4Ghz Xeon Quad to under 65'c load, two of them together would give comparable performance to your hex-core at 4.6 and have a cooling solution a tenth the size seems a bit odd.