All mini-ITX mainboards based on the Intel Z77 chipset provide some overclocking settings and we’ve focused on them in our descriptions above. And while the basic features (CPU multiplier and memory frequency adjustments) are available in every mainboard’s BIOS, their voltage regulation capabilities may vary. That’s why we’ve summarized them in the following table.
The ASRock Z77E-ITX and ASUS P8Z77-I DELUXE offer as much flexibility as possible, providing a full selection of overclocking options. The other mainboards allows increasing CPU and memory voltage too, but have no such flexibility and you should be aware of their limitations. The only exception is the Gigabyte GA-Z77N-WIFI which offers but basic overclocking capabilities and doesn’t allow to change any voltage save for memory voltage.
A mainboard’s CPU overclocking capacity is not limited to its voltage management. Its VRM design and stability at high loads are important as well. That’s why we want to test our mini-ITX mainboards at overclocked settings.
Our testing method is somewhat different from what we normally use in our mainboard reviews. Mini-ITX systems have certain limitations concerning their cooling. That’s why we don’t increase CPU voltage above 1.3 volts and try to make the CPU work at 4.4 GHz. Our Core i5-3570K should be perfectly stable at that clock rate. We also try to change CPU voltage by using an offset rather than an absolute value to keep power-saving technologies up and running.
Every mainboard can keep the Core i5-3570K stable at 4.4 GHz, except for the Gigabyte GA-Z77N-WIFI which is limited to 4.3 GHz. We had to use an absolute voltage value for the EVGA Z77 Stinger and MSI Z77IA-E53, so their power-saving technologies were turned off. Besides, the EVGA Z77 Stinger was unstable with our DDR3-2133 SDRAM, so we had to lower the memory frequency to DDR3-1600 to let the mainboard pass through all of our stability checks. The results are shown in the following table.
We measured the temperature of the VRM components during our stability tests to see how efficiency they are and how they can sustain CPU overclocking. It is undesirable for mini-ITX systems to have too hot components.
The EVGA Z77 Stinger and Zotac Z77-ITX WiFi have the lowest VRM temperature, both mainboards featuring massive heatsinks on their hot components. The Gigabyte GA-Z77N-WIFI has no VRM cooling at all, so its DrMOS chips get very, very hot. The ASUS P8Z77-I DELUXE is surprisingly hot, too. This mainboard has a 10-phase VRM on a daughter card and its temperature is above average for some reason.