X Server throttles overclock after awhile

I’m running Ubuntu 16.10 and I have a Gigabyte Geforce GT 420 with 2Gb Vram (Driver versions 367 & 375).

I’ve overclocked it using (Option “CoolBits” “28”) in the xorg.conf and set the clock and memory offsets to 167 using the following startup scripts: (nvidia-settings -a “[gpu:0]/gpugraphicsclockoffset [2]=167”), (nvidia-settings -a “[gpu:0]/gpumemorytransferrateoffset [2]=167”), and (nvidia-settings -a “[gpu:0]/GPUPowerMizerMode=1”).

Why 167Mhz offset you ask? That’s the “Sweet Spot” and produces 0 errors according to the Phoronix Test Suite test: “x11perf”, even the stock frequencies produce errors.

Everything boots, starts and runs perfectly. However the X server throttles my GPU to the middle mode “1” after a few minutes of running, even with (nvidia-settings -a “[gpu:0]/GPUPowerMizerMode=1”) being used.

I’ve also tried all the: (Option “RegistryDwords” “PowerMizerEnable=0x1; PerfLevelSrc=0x2222;PowerMizerDefaultAC=0x1;”) crap and that doesn’t work either.

Is there another way to force it to full bore all the time?

I realized I ran these tests before I applied a Bios PCIe multiplier of 10 (max).
It also produces 0 errors with base clock frequencies using the same Phoronix Test Suite test: “x11perf”