Cpu temperature reaches up to 68º in full performance, maybe too much? if so, I would put a new heatsink on it, but what orientation would I give it… :eoh:
Surely the cpu is "eating all the heat from the graphics", or so I think.
First… 68ºC on the CPU is nothing... it could perfectly be working for years without stopping at 90ºC and it wouldn't give a single problem because the micro starts to suffer from 100ºC... so forget about the CPU.
As for who eats the heat that doesn't matter... the case must be well ventilated and should never exceed 40ºC inside (in case you wonder, these are the manufacturer's specifications).
That is, you must have an input/output flow that introduces cold air and takes out all the heat generated.
The greater that flow is, the closer to the ambient temperature the inside of your case will be.
If the case is not well designed, it helps to improve efficiency by putting fans inside as Fassou has told you, although it is a noisy solution and I don't like it.