There is no real equivalent as intel cpu's single core performance is better than amd. You can find some equivalent in performance, but always there will be individual differences because the lower end intel, which perform about the same as the fx8320 are quad cores, compared to the 8 core fx 8320. Also benchmarks change when the cpu's are being overclocked.
Here are some benchmarks to compare:
http://www.cpubenchmark.net/cpu.php?cpu=AMD+FX-8320+Eight-Core
http://www.futuremark.com/hardware/cpu/AMD+FX-8320/review
http://www.cpu-world.com/benchmarks/AMD/FX-8320.html
http://www.anandtech.com/show/6396/the-vishera-review-amd-fx8350-fx8320-fx6300-and-fx4300-tested/1