So, lemme link you to something first.Intel Core i5-2400AMD Phenom II X6 1055T
Lemme give you the breakdown from those pages.Overall Benchmark Score
Intel Core i5-2400: 6045
AMD Phenom II X6 1055T: 5192What this means is that, overall, benchmarking with Passmark's software shows better results with the i5 than the Phenom. This is using standardized tests that every processor can and will be expected to do pretty much every time you use it. However, take these results with a grain of salt, since that i5 is new and Passmark has roughly six times as many submitted benchmarks for the Phenom.Overall Rank
Intel Core i5-2400: 54
AMD Phenom II X6 1055T: 74This one is a bit self explanatory. Passmark has a ranking system that ranks processors by their overall score. In this case, lower is better, and the i5 places significantly better in the rankings than the Phenom, though they both rank in the high end CPU page.CPU Value
Intel Core i5-2400: 31.98
AMD Phenom II X6 1055T: 32.47This one takes a bit of explaining. Passmark tracks the CPU prices on certain sites, and uses the lowest value on those sites to generate this. They do so by dividing the overall score by the lowest price they found. Obviously, higher is better, meaning that, the last time they indexed it, the Phenom was a slightly better value. However, you have to take these results with a grain of salt, because they may have calculated these with a price that's different from the one you payed. In other words, to determine this value for the prices you found, just take the CPU's overall score (the first one I went over) and divide it by the price you found. Whichever has the higher number will be the higher value, by their system.
Also, about offloading onto other cores, etc. That's pretty much automated, and is highly dependent upon OS and how the software was programmed. One thing to note is that most configurations of Win7 actually put one or more cores to sleep on multicore processors, for no apparent reason, and it often takes tweaking the registry or bios to leave them active.