FrostyTech posted a review on the AMD Athlon II X4 645 3.1GHz Socket AM3 Quad-Core Processor

PCSTATS is testing AMD's latest mainstream quad-core chip, the 3.1GHz Athlon II X4 645 processor. Architecturally speaking the Athlon II X4 645 is identical to the preceding Athlon II X4 635 model, except for a modest clock speed increase. If you're familiar with the preceding few Athlon II X4 6-series CPUs you'll know what to expect so jump ahead to the overclocking results and benchmark tables. Bringing the AII X4's four cores past the 3GHz threshold affords incremental gains of course, and the Athlon II X4 continues to be an ideal CPU for media PCs, particularly when paired an AMD 890GX motherboard.

  AMD Athlon II X4 645 3.1GHz Socket AM3 Quad-Core Processor Review