Hello
Whenever I play WoW classic TBC i’m experiencing random CPU spikes every 30 sec to 2 minutes.
It’s completely random, it can happen anywhere in any area in the game. It even happens in the character screen.
I would have never noticed if my cooler wouldn’t roar up like crazy when it happens.
My CPU usage usually sits around 3-5%, when the spikes occur it goes instantly up to 20-30% for approximently 5 to 15 seconds and the fan of my watercooler roars really loud due to the sudden CPU usage increase, then it returns to normal only to have it happen again after 30sec to 2 minutes.
I experience no performance loss when it happens, it’s just really annoying to have the fan roar all the time and then goes to complete silence again.
It happens on the character screen without addons, completely random.
When I look in the taskmanager when it happens I can see the cpu in WoW goes up from 1% to about 20%, stays there and then after 5 tot 15 sec it returns to 1% again.
What could be the cause of this?
Reinstalling the game didn’t solve the issue.
This is a bit of an odd one. Generally speaking, 3-5% CPU load sounds pretty low for any game to be tracked at outside fully idling on the login screen - but beyond that, it genuinely sounds like the cooling/fan profile may be incorrectly set up here.
20-30% core-load shouldn’t necessarily cause an extreme response from the cooling system, especially since temperatures wouldn’t very drastically rise within just a few seconds of higher load. Not sure we can recommend much here apart from possibly taking a look at how threshold/default values for the fan-curve are set. 
Well the thing is when the spike occurs the core jumps up in clock speed, which makes the core jump up in temperature.
I have monitored my CPU when the spike is happening, basicly the voltage of the cpu sits around idle and then suddenly it spikes to max voltage, very violent behaviour of my ryzen 5 5600x. The CPU usage is ingame around 5% then the cpu suddenly goes up to 30% and stays there for like 5 seconds.
I don’t know why wow is suddely using so much cpu every 2 minutes, 30% then back to the usual 5%. it’s really annoying.
I found a similar thread here: High CPU usage randomly
There is nothing in WoW itself that could cause this, so unfortunately we won’t be able to fix this from our end - but there are background programs that regulate/throttle voltage supply and fan-speeds. If any of those were to be going off the rails the result would almost certainly look a lot like described here.
You would need to use Microsoft Process Explorer (or just Windows tasks list):
https://docs.microsoft.com/en-us/sysinternals/downloads/process-explorer
To actually see if it’s WoW or something else doing that. There are cases some overlay apps or background tasks go crazy sometimes and have to be turned off or restarted.
Also % CPU usage is very imprecise - you need time graphs to see which core is doing what. Pure % sampling as a value is prone to weird numbers due to how it averages data.