Now I run the same tests with the CPU and memory overclocked. The difference in system parameters can be seen in the table:
The first three tests focus on the computing performance and depend on the CPU clock rate, so the mainboards split up into two groups depending on the CPU clock rate they reached, 4.7 or 4.8 GHz. The Foxconn stands apart from the others because it could only overclock the CPU to 4.5 GHz (a BIOS bug prevented me from increasing the CPU voltage). The Gigabyte GA-Z68X-UD7-B3 takes an in-between position because its CPU frequency was 4.7 GHz, but its memory worked at 1867 MHz with 7-7-7-20-1T timings. The memory frequency of 1867 MHz did not help the Gigabyte GA-Z68X-UD5-B3 model because I had to use high timings of 9-9-9-24-1T for it. As a result, its performance is the same as that of the mainboards with a memory frequency of 1600 MHz and lower timings.