5000 1.28V should be impossible for air/water, probably he uses dryice/LN2, maybe even the voltage is incorrect, but even if 5000 1.28V is real, and 5Ghz is max stable clock - this CPU is very bad on scaling or has a very limited bclk-wall
This board is much better than i expected, BCLK 210+ and higher memclk easy possible with Bloomfield CPUs, but with Gulftown max memclk is around 1530-1550, something is broken in the BIOS