Half of CPU Cores are at 50% load randomly

SergNMerp · April 18

Firstly, I'm not home with my PC at the moment so I can only give off details off the top of my head,
Secondly, I know this has got to be an OS/Software issue because this is the 2nd processor this has been happening to.

Alright, so, few months ago I noticed with my R7 5700G that my temps while idling (few browser tabs, discord, telegram, youtube video, nothing intensive) were a little higher than usual, higher than it would be at idle, so I open up Core Temp, see that 5 out 8 cores are around 50% load. Weird, so I open up task manager to see what was causing that, and the second task manager opens, suddenly all the cores are back down to 0-5% load. Close task manager, cores remain at 0-5% usage, odd but whatever. Some time later, same thing happens, 5 out of 8 cores at 50% usage, open task manager, suddenly 0-5% usage, whatever. This has been constantly happening (several times an hour) since whenever that started those months ago.

It wasn't a big deal to me at the time because the 5700G being an APU, the G classifcation aimed towards office pcs, low TDP, didn't produce much heat so I didn't really care, but now that I've upgraded to AM5, with an R9 7900X, that beast has almost 3 times the TDP of that 5700G, little bit more concerning. Since then, I've recently gotten the Arctic LF3 360 AIO, and now with the same issue happening with the 7900X, like 6 or 7 cores are randomly at 50% load, plus the fact this ROG mobo likes to keep her clocked at 5.something GHz almost all the time, she puts off a fair amount of heat. Nice in the winter, but living in Texas with this spring/summer heat coming on, it's been in the 80's outside daily and now my room is quite warm, too warm. Should note that my ceiling fan is broken (runs low speed at high speed setting), and the little Honeywell desk fan in the corner of my setup is running full speed 24/7, room is still pretty warm regardless.

I will note, I do keep my pc on nearly 24/7, HOWEVER, that is solely because of an entirely different shitshow that I will make a different troubleshooting post for. If it wasn't for that other issue, I'd usually put my pc in hibernation mode overnight and shut down if I'm out of town/gone all day.

AMD R9 7900X
ARCTIC LF3 360
ASUS ROG B650E-F
G.SKILL Flare X5 2x16GB DDR5-6000 CL32
MSI 6650 XT Mech 2X
SAMSUNG 980 Pro 2TB
CORSAIR RM850x 80+ Gold
~
Windows 10 Pro - Build 10.0.19045.4291 - Version 2009 (according to my microsoft account info about my rig, again not currently home to check)

I've tried to search up this issue on the web and came across a couple random forums of people having a kinda similar issue, but the answers said something along the lines of File Explorer doing something in the background, which I know mine ain't doin jack unless steam's updating a game, possible malware which I doubt but also who knows; I just use defender and stay off the sketchy sites, generally no useful answers overall though.

Will also note I plan on doing a windows reinstall here soon, not just a fresh install but also to clear up some old applications, drivers, and the sorts that are lingering around despite being supposedly removed, and perhaps encite myself to properly orgnanize some files as well.

Just an old screenshot I have saved, when I get home I'll update with some updated and more detailed screenshots.
(don't worry about the 94c, like I said this is an old screenshot, with the LF3 the max temp is in the mid 80's)

also making this in a bit of a rush so, little sorry if anything's weird with my post

SpaceGhostC2C · April 18

58 minutes ago, SergNMerp said:

Alright, so, few months ago I noticed with my R7 5700G that my temps while idling (few browser tabs, discord, telegram, youtube video, nothing intensive)

That's not idling, though.

58 minutes ago, SergNMerp said:

Some time later, same thing happens, 5 out of 8 cores at 50% usage, open task manager, suddenly 0-5% usage, whatever.

Don't close task manager. Keep it open, sorted by CPU usage, together with coretemp. Keep both visible. As soon as CPU usage increases, check whose causing the spike. If it never happens, use your computer with task manager open forever, but I doubt it'll be that simple

SergNMerp · April 18

3 hours ago, SpaceGhostC2C said:

That's not idling, though.

Well, whether or not it's idling for a computer in the technical technical terms, it's as idle as it'll get for what I do with it. Still shouldn't be causing this issue though, my guess is that it should be about 5-20% on a few cores like how my laptop is, of course not the exact same way being a little far apart in the field of processors, but still.

3 hours ago, SpaceGhostC2C said:

Don't close task manager. Keep it open, sorted by CPU usage, together with coretemp. Keep both visible. As soon as CPU usage increases, check whose causing the spike. If it never happens, use your computer with task manager open forever, but I doubt it'll be that simple

Yeaaahhh, I remember some of the further testing I've done, at least when I had my 5700G, I left task manager open for a couple hours and as far as I know, the issue didn't pop up.

I do recall that when I got the Corsair Link H150i, I could easily tell when this issue popped up coz the fans would go jet turbine status, I'd check core temp, it's the issue, open task manager, fans die down after a sec, yeah. Hell, that screenshot above is from when I had that AIO installed, with the temps going into the 90's easily I figured pump must've been defective, so I returned it and got the LF3 instead.

Aaaanyways, will do some further testing, see what's a good temporary if not permament solution, see if the windows reinstall fixes it (gonna be a hot minute before that happens though), and then keep note of what I install in case it pops up again. Keeping task mananger open might be fairly doable, will have to disable priority window (whatever it's called, makes it so it always appears over other applications), keep it on my 2nd monitor somewhere, yea.

SpaceGhostC2C · April 18

2 minutes ago, SergNMerp said:

Well, whether or not it's idling for a computer in the technical technical terms, it's as idle as it'll get for what I do with it.

It doesn't matter, as long as you have a couple programs actually doing something, some spikes to some degree in some cores could happen. The issue is how often, how high, how many... But that's harder to tell.

2 minutes ago, SergNMerp said:

Yeaaahhh, I remember some of the further testing I've done, at least when I had my 5700G, I left task manager open for a couple hours and as far as I know, the issue didn't pop up.

If you are never able to spot it in real time, it makes it more likely that it's some background task (antivirus, windows updates, indexing, etc.) taking some of your activity as "idling", but deciding you are "active" when you open task manager or something else (technically, your computer is always running something, so there is some decision making involved in triggers based on "idling" or not. You can notice similarly inconsistent behavior with monitors sleeping, screensavers, etc.).

2 minutes ago, SergNMerp said:

Aaaanyways, will do some further testing, see what's a good temporary if not permament solution, see if the windows reinstall fixes it (gonna be a hot minute before that happens though), and then keep note of what I install in case it pops up again. Keeping task mananger open might be fairly doable, will have to disable priority window (whatever it's called, makes it so it always appears over other applications), keep it on my 2nd monitor somewhere, yea.

Yes, even if it works, ideally you want to find out the culprit, so you can decide if you want to accept it or not. I don't know if there's any program (that won't be detected as task manager) that can log CPU usage by application in the background, so you can check ex post.

SergNMerp · April 19

Ended up pulling an all-nighter, kept task manager open but minimized the whole time, was mostly just window shopping, didn't play any games, average temp was in the low 50's, didn't feel a warm breeze on the top of the case (top mounted rad). Yeah, it didn't do the 50% thing, so I figure this'll be the farmer's fix (can't remember the exact phrase, but temporary fix working good enough it's now permanent) till I reinstall windows, just need to remember to not close task manager.