Now that we’ve defined the circumstances under which three motherboards had failed in our previous review, we can fully evaluate the improvements that ASRock and MSI provided. Our previous page shows that our processor consumed over 200W when fully overclocked at 1.45V, while ASRock’s engineer told us the P55 Pro’s voltage regulator is designed to sustain 150W. While many might suspect a hardware change might be required, ASRock already had a hardware solution designed into its motherboard.
It turns out that the motherboard already had over-current protection built-in, and ASRock had simply neglected it in the BIOS, believing that average overclockers wouldn't need it. A BIOS update to version 1.80 was the sole requirement to fix the P55 Pro, and ASRock even had Newegg ship a retail sample from its normal stock to prove this.
MSI stated that the board we received was produced prior to retail distribution and replaced it with exactly the same model. We went over the board in great detail trying to find any component changes, but there weren’t any. Whatever the defect of the previous sample, we put the new one through its paces using the same BIOS version found in our original review.
We were first pleased to find that a simple BIOS update allowed us to fully test the P55 Pro’s overclocking capability without a single sign of fatigue to the board. It completed several hours of eight-thread Prime95 stress testing at 1.35V, and dutifully shut off when we tried to apply even more stress through increased voltage and clock speed. The only way to push further without triggering the voltage regulator’s safety switch was to test at lower stress levels, and though that’s not practical for assuring 100% stable operation, disabling some cores might be. Intel is, after all, throwing out hints at an upcoming dual-core LGA 1156 processor (the 32nm Clarkdale).
The MSI P55-CD53 was limited to far less voltage, and our 1.25V test was the practical limit of the board. Unlike ASRock’s solution, the P55-CD53 would only shut down the CPU voltage regulator in response to a high thermal load. A blank screen resulted whenever we tried to apply more than 0.210V of offset voltage, which is the only method this affordable MSI board provides for CPU-voltage adjustment. Further prodding proved the tiny voltage regulator sink was the culprit. We’ll never know how much power the motherboard could potentially provide, simply because thermal protection kicks in long before over-current protection would be needed. However, the fact that this protection mechanism works very well is enough for us to withdraw any concerns about using it at or near stock voltage.