PoE Performance Metrics/Graph: CPU spikes when moving mouse

I've suddenly begun having this issue minutes before finding this thread.

Holding left mouse stops it from lagging. Nothing to do with walking either? it persists when doing other things (set LMB to summon a totem and swing your mouse around while holding, no lag.)

I go from 200~fps to 10fps with a huge CPU response time spike. I don't have any other mice to test it on.

It doesn't make sense for it to be the mouse itself (Microsoft Intellimouse Pro) as it was working last night and this morning.

Any thoughts?

Tldr:
No solutions sorry. However, the easiest and most likely workable workaround is to disable engine multithreading in PoE's settings. It'll probably increase the CPU bar value a bit but will also probably result in less CPU spikes.

Please do post any thoughts, brainstorming, or fixes/workarounds you come across.

---

Hey. Sorry for not reporting my 'findings' sooner but I haven't actually finished testing (I had to put testing on hold: I was devoting too much time to this issue and neglected work for about a month; about a month after I put this on hold I'm still badly behind with work). I received two other messages outside of this thread asking for an update on this issue so it seems that others are encountering it also.


Identifying the issue: This is what I've discovered so far about this issue (your results may differ); please keep in mind this is still very rough since it's still an ongoing investigation with no actual fix or even identification of cause:

• It's not PoE: I used the HTML/JavaScript mouse input performance tests page at vsynctester.com to help visualize the problem and found that it occurs outside of PoE. PoE is likely just more sensitive to mouse lag or something (PoE also now provides a handy in-game visualizer so that may increase detection while in-game).
• It's not the mouse: Different mice at the same polling rates didn't provide noticeably different results. I tested with the following mice:
  • Redragon M601-3 (1000Hz)
  • Steelseries Rival 100 (@1000Hz, 500Hz, ?250Hz? <- not sure about the Hz for the lowest test)
  • Microsoft Basic Optical Mouse v2.0 (Model: 1113) (125Hz)
  • Ativa Lynx-R19R (125Hz I think)
  • Riitek M01 (1000Hz)
• The higher the mouse polling rate and the slower my CPU clock the more this issue shows up. I found that the issue is minimal and nearly ignorable at a polling rate of 500Hz or less at 4.4GHz ish.

Workarounds: These may help (but almost certainly won't solve the underlying problem); keep in mind that none of these workarounds 'removed the symptoms' enough to satisfy me--I only stopped troubleshooting because I couldn't justify the time spent on this vs (the lack of time spent on) work:

• First off: Take control of your computer. Don't let it do 'things' while you're trying to game. Period. Common 'things' computers love to do while we game:
  • 'Security' scans
  • Defragments
  • Updates
  • Checking for updates
  • Relaying telemetry
  • Honestly the list goes on and on. If you're serious about disabling bloat just open Resource Monitor (Start -> Resource Monitor) and take a look at what's running. I like the Disk tab because it shows any program that's accessing any disk. I then find out what it is (web search it), why it's running, and if it can be disabled or removed (if it's something that needs to run occasionally I add it to a list of programs to run manually--on my schedule!). The Memory and CPU tabs are great too since they can be sorted to show 'expensive' programs ripe for culling.
• Disable engine multithreading in PoE's settings. CPU time might increase but also might be overall more stable with less/no 'unprovoked' spikes.
• Restart your computer.
• Try a mouse with a lower polling rate (or reduce the polling rate if your mouse supports that).
• Disable CPU C-States.
• Just max out your CPU using a tool like Cinebench (it's weird but back when I was testing the 'Pulsating CPU bar when near certain effects' issue the pulsation disappeared when I ran PoE while maxing out my CPU with Cinebench). This isn't even a workaround really but can be interesting for diagnosing the problem.

My next steps (on hold):
My next tests are/were going to be doing a full OS reinstall using default settings and zero post-install configuration (and no 3rd party tools), then re-configuring slowly until the problem returns. If the problem exists on a fresh default install I would test with other hardware (ie: a different computer) and see if the issue is present on a fresh install there too. If so I'd go to Microsoft support and find a pleasant Linux distribution to use I mean test with in the meantime.


Helpful and related web (browser) tools for mouse troubleshooting:

• Check the polling rate of your mouse: https://devicetests.com/mouse-rate-test
• Check the input delay of your mouse: https://www.vsynctester.com/testing/mouse.html This needs to be opened in a browser that doesn't collapse mouse events (ie: old Internet Explorer oddly enough; Chromiums (Chrome, Modern Edge, etc) and Firefox all collapse mouse events so all that page shows with them is the monitor's refresh rate, not too helpful).

My videos showcasing the issue:

• Using the input delay webpage to test different mice: youtube?v=GI_SesWUCns
• More of the above without the system information: youtube?v=HKnr31DZy8o
• PoE CPU bar spikes when moving mouse with a Ryzen 9 5950x (@4.44GHz ish and 5%ish CPU utilization): youtube?v=WVXj7kh4z9c

I actually came back here to post a reply about it not being just POE. I had it happen on minecraft. It's definitely a system wide issue that can happen randomly and once it "procs" so to speak, it won't go away until I restart my computer. It seems weird that it's something I've never run into before and makes me wonder if there's any settings or updates related to it that might have changed.