You are running an AMD quad @3.4GHz. AMDs run hotter than Intel - they always have. Every computer I have ever built over 15 years is an AMD and they all run hotter than an Intel chip. I have an older AMD quad in my present box that defaults to 3.0GHz, and I overclocked it to 3.4 and now it runs at 50°C idle. I also went with liguid cooling and that knocked several degrees off. Liquid coolers now are as cheap as air, and far more efficient and quiet. I now build only with liquid cooling, I will never use air again. Just a thought. 75°C is a bit high under load, but modern CPUs can go as high a 90° and not melt down. I am not suggesting you allow that high, I am just setting parameters.
Apologies for going off-topic for a minor point...but actually...I think that you have it backwards .
I've used AMD CPUs almost exclusively and...if you check out the specs for the thermal ceilings (max temperature)...you will see that, although each processor is somewhat different..;.it's the Intel processors which generally have the higher ceilings (up to 102 Celsius), while the AMD CPUs generally have max temps of no more than 72 Celsius.
The inference is that the Intel CPUs can certainly run at higher temps than AMD CPUs, IMO...and are more likely to do so. I've looked at a large number of CPU temps and looked up the max temps for any number of CPUs where data here was posted via Speccy...I think your assertion goes against the grain. You can find the max operating temps for just about any CPU...at the cpu-world website, for one.