For video rendering, Intel stomps AMD. This is mostly due to AMD's poor implementation of the streaming data instructions. There are only a handful of applications which make use of anything more than two cores. Most all of them are video editing based.
I have nothing against AMD, but I still do not like any of the chipset solutions available for them. They still are the most problematic computer systems I deal with on a daily basis. Given they have such a small percentage of the overall marketplace, it gives me even greater cause to avoid them.
In the real world, a faster clocked CPU, with fewer cores, will work better than a slower clocked CPU, with more cores. Even when the clocks are the same, there is a point in which more cores simply do not get much in terms of performance due to all the bus arbitration and bus contention issues.
Notice, I keep using the phrasr, "in the real world". I can craft all manner of benchmarks or load balanced solutions to show how wonderful a bazillion core CPU would be, but that would be just for marketing purposes as most real world software simply does not derive any, or much, benefit from multi-core CPU's.