|BIOS Frequency and Voltage settings (for overclocking)|
|ASRock Z68 Extreme4||Asus P8Z68-V Pro||Gigabyte Z68X-UD3H-B3|
|CPU Base Clock||95-110 MHz (0.1 MHz)||80-300 MHz (0.1MHz)||80-200 MHz (0.1MHz)|
|CPU Multiplier||Up to 60x||Up to 59x||Up to 59x|
|DRAM Data Rates||1066-2133 (266.6 MHz)||800-2400 (266.6 MHz)||800-2133 (266.6 MHz)|
|CPU Vcore||0.60-1.70 V (5 mV)||0.80-1.99 V (5 mV)||0.75-1.70 V (5 mV)|
|VTT Voltage||0.66-1.87 V (13 mV)||0.80-1.70 V (6.25 mV)||0.90-1.53 V (5 mV)|
|PCH Voltage||0.78-1.65 V (9 mV)||0.80-1.70 V (10 mV)||Not Adjustable|
|DRAM Voltage||1.20-1.80 V (15 mV)||1.20-2.20 V (6.25 mV)||0.87-2.13 V (5 mV)|
|CAS Latency||5-15 Cycles||3-15 Cycles||5-15 Cycles|
|tRCD||4-15 Cycles||4-15 Cycles||1-15 Cycles|
|tRP||4-15 Cycles||4-15 Cycles||1-15 Cycles|
|tRAS||10-40 Cycles||4-40 Cycles||1-40 Cycles|
Does enabling our Core i7-2600K’s integrated GPU severely limit its overclocking capability? We wanted to find out.
While the P67 motherboard leads slightly in overclocking, it also comes from a higher-end product line. The difference of a few MHz between the two Asus motherboards is less than the difference we’ve seen between two identical motherboards pulled from the production line at different times.
The only motherboard to suffer under our CPU overclocking test, Gigabyte’s Z68X-UD3H also has the least-elaborate voltage regulator. That’s appropriate for the lowest-priced board in the roundup.
Gigabyte does achieve a higher base clock, in spite of its simpler voltage regulator. That could be important for overclocking “locked” processors, though high base clocks have been known to slowly damage LGA 1155-based chipsets.
The P67 platform leads in DRAM overclocking, and that could be due to the integrated GPU being enabled on its Z68 competitors. Then again, Asus is often good at memory overclocking, and the P8Z68-V Pro might just be an exception to that rule.
In fact, the reason the P8Z68-V Pro has a comparatively low four-module overclock is because the motherboard kept shutting off when we pushed those modules. This appeared to be due to overcurrent protection, which makes sense because this Z68 motherboard has a “one level lower” voltage regulator than its P67 sibling.