Hi Tech Legion posted a review on the EVGA X58 3X SLI Classified Motherboard

The process of overclocking the Core i7 920 CPU on the EVGA X58 Classified motherboard was a fairly straightforward experience. I began with simple 5 MHz increases to the front side bus and running OCCT to stress test the overclock for 20 minutes. I hit a wall at about 180 MHz at stock DRAM and core voltage settings. I then began to boost the voltages to the VCore, the QPI core, the DRAM. With several different combinations of voltage adjustments and RAM timing and speed adjustments, I was able to establish a maximum overclock of 4.3GHz, with temperatures hovering around 80 to 85 Celsius. These temperatures are a little on the high side and I prefer stability and longevity to achieving benchmarks that could cost me a system. The CPUz and information on the stable 4.3GHz overclock are provided here. I did, however, maintain a stable 4.2GHz overclock that stress tested at only 75 to 78 Celsius, which is deemed as acceptable for benchmarking and longevity of the chip. All overclocking benchmarks will be performed at this 4.2GHz overclock. This overclock was achieved with a bus speed of 200 MHz, a RAM ration of 2:8 resulting in RAM speed of 1600 MHz, and a QPI multiplier of 16x. Voltages in the core were at 1.45, which required extensive modifications to the CPU heatsink and additional active cooling to the north bridge and to the 6 sticks of RAM. The cooling modifications are also pictured below to demonstrate what is needed to achieve this 57% overclock on air cooling. It is worth noting that there is more headroom to this chip with increased VCore voltages if there is a water cooling or more extensive cooling setup.

EVGA X58 3X SLI Classified Motherboard Review