While not a straight-up comparison due to hardware platform differences that can't be changed and having different x86/ARM stacks, this isn't 100% accurate, but I ran some tests against various CPUs. The compared hardware includes the AMD FX-8350 and then the Intel Core i3 2120, Core i5 2400S, Core i5 2500K, Core i5 3470, Core i7 3770K, Core i7 3960X, Core i3 4130, and Core i7 4770K. The result file was taken from last week's Intel Core i3 Haswell Linux review.
These new ODROID-XU results can be found on OpenBenchmarking.org within 1310227-SO-CORECOMPA87. See how your system stacks up to these configurations by installing the Phoronix Test Suite and then run phoronix-test-suite benchmark 1310227-SO-CORECOMPA87.
Of more relevance than comparing an ARM SoC to high-end Intel Core CPUs will be Atom benchmarks. As luck would have it, today I bought an Atom "Bay Trail" laptop for Linux benchmarking and so it should be interesting to see how the performance compares to the brand new Intel Atom. Stay tuned!