Is it normal for CPU temp to spike around like this?

[Ajido]

The CPU (7700K@stock) temp seems to spike up and down very quickly as the usage increases/decreases. Is it normal for the temps to change at that speed or should it be more smoothed out? I had to take my heatsink off yesterday, just wondering if I've made a mistake in the reinstall/reapplication of thermal paste. When I run the Stress test included with CPU-Z it seems to top out at around 78-80C, but the idle stays low-mid 40C.

[Skiiwee29]

Thats normal, as you do things such as open a program, load a web page etc.. it all has to process through the CPU and you can see upwards of 10-15c temp spikes during this, completely normal. 

[jonrosalia]

the spikes follow usage and don't get crazy so it looks fine under 80c is a great place to be if your doing a stress test.

[Ajido]

Just now, jonrosalia said:

the spikes follow usage and don't get crazy so it looks fine under 80c is a great place to be if your doing a stress test.

The Aida64 test put it closer to 90C though, is that something I should be concerned about?

[jonrosalia]

no I wouldn't worry about that that's pushing the CPU to its max and kinda unrealistic unless you see temps in use at close to 90 don't worry if you do try a thermal paste re application your not going to hurt anything unless you see it running over 100c extended remember MacBooks run at 100c+ factory with intel chips (seen 108c) that's scary to me.