Gaming does NOT present 100% loads. 100% on one, or a few cores, is not equivalent to "full load" temps. Full load is all core 100%, steady state. Steady state being the key. Fluctuating workloads are no good because cores have time to "rest", so saturated package thermals are never reached or sustained.
Your idle temps are way too high. You have either too much voltage for your hardware or your cooling is not up to the task. Or, you do not have a satisfactory mount or thermal paste job on your cooler. I would double check that the backplate to mounting bracket hardware is snug and that you are tight on all corners/sides of the water block to bracket hardware. Also, that you removed any protective cover from the bottom of the water block before installation.
In truth, it sounds like your pump is not operating normally. Do you have the pump configured for 100% RPM operation at all times, because that is what it SHOULD be configured for. Only your fans should be configured for variable rate operation. It's possible there could also be an air bubble.
If all that is as explained, then you may simply be using too much voltage. 81°C under ANY kind of gaming load, is too high. It MIGHT be, just barely, acceptable, (80°C and no higher is what we really want to see for Core-i processors whether overclocked or not when under a full load) if you were getting those temps while running Prime95 on the Small FFT option with AVX/AVX2 disabled, but not for gaming or other non-steady state benchmarks or utilities.
Full testing and guidelines can be found here:
Covering the basics If you found your way here it's likely you are looking for help with basic overclocking. Either that or you're a long time overclocker interested in seeing whether I had any eye opening insights that you may have been lacking. Rest assured, I don't. This is only intended as...
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