Overclocking
Although it's still early days, Lynnfield appears to be a willing overclocker. You have two options with the boards we're looking at today: kick it old-school by cranking base clock speeds or use trendy new auto-overclocking features that seem to be all the rage. We've tested both, and I'll start with the retro approach.

To probe each board's base clock speed limits, we dialed back the CPU and memory multipliers to take them out of the equation. Next, we ramped up the base clock speed, testing for stability along the way with a combined Prime95/rthdribl load.

The UD4 effortlessly cruised up to a 210MHz base clock speed without so much as a bump in voltage. 220MHz wouldn't post, though, and tweaking processor and chipset voltages didn't help. I even tried relaxing memory timings, but the UD4 stubbornly refused to cooperate.

Like the UD4, the GD45 reached its peak stable base clock speed without extra voltage, and upping the voltage didn't help. The board only made it up to 200MHz, but that's still pretty respectable, and more than enough headroom for air-cooled processor overclocking.

What's most interesting about these results is that they don't stray from the peak base clock speeds we've achieved with full-size ATX boards from Gigabyte and MSI. That's promising news for anyone leery of overclocking with a MicroATX mobo—well, these ones, anyway.

Next, we turned our attention to the auto-overclocking schemes offered by each board, starting with the UD4. Gigabyte's Smart QuickBoost software selects a CPU clock speed based on the company's own experience overclocking the processor in question. With our Core i5-750, QuickBoost settled on a 160MHz base clock speed. With Turbo Boost, that took the CPU up to 3.36GHz on just 1.216V.

This is the same clock speed that QuickBoost chose for the processor when we ran it on the UD4's ATX siblings. Our i5-750 seems to be perfectly comfortable at 3.36GHz, too, even under a demanding four-way Prime95 load.

MSI's approach to automatic CPU overclocking revolves around an OC Genie BIOS switch. Enabling OC Genie automagically overclocks the CPU at the next reboot, and it arrived at a somewhat different conclusion than QuickBoost.

OC Genie actually lowered the system's CPU multiplier to 17X and then cranked the Base clock speed past 190MHz, pushing the CPU to 3.27GHz. That's a little slower than what QuickBoost achieved, and it required a smidgen more voltage—1.312V, according to CPU-Z.

While I prefer overclocking the old-fashioned way, I do appreciate the fact that OC Genie doesn't require Windows software. Of course, if the point of an automated approach is to bring overclocking to users who would otherwise be intimidated by poking around in the BIOS, Windows software might actually be preferable.