Intel CPUs will run at their full rated speed right up until they hit the thermal throttling temperature. This happens when your CPU reaches 100°C. A peak temperature over 80°C might be a little high but this temperature will not cause the CPU to slow down. Buying a better heatsink and fan will allow your CPU to run cooler but it will not allow it to run any faster. Do not waste your time or money on a new cooler.
The specs for the Core i5-4570 shows that when 4 cores are active, the maximum multiplier is 34.
Your CPU is running at its full rated speed. It can only use the 35 and 36 multipliers when less cores are active. You also need to have the core C states enabled in the bios.
zedxer reacted to unclewebb in CPU not turbo boosting under load with high temperature.
