For overall system performance we use PCMark Vantage; this is run in both x86 and x64 mode to give the best indication of performance.
At 24 minutes a run this is not something that would often be used in conjunction with LN2, but here you can see it scaling with the added speed. I capped this at 5GHz due to the length of time and the amount of LN2 required to find the absolute maximum speed for this benchmark.
I also ran into another obstacle; the Seagate XT drive suddenly and without warning failed. Unfortunately it had a number of saved results including the 64-bit runs of the above benchmark. There is insufficient time to source a replacement and as the hard drive affects the end score, it is not suitable to substitute it with another.