Video: https://www.youtube.com/watch?v=cLKHb7DwtEk
I recently came across an incredibly bizarre issue on Windows 10. Here’s the gist: In games, on higher core CPUs (6-core Coffee Lake in this case) when the CPU hits 100%, the mouse movement becomes inconsistent and unreliable. I’d highly encourage you to watch the video documenting the issue because it’s less like mouse lag and more like the mouse isn’t receiving proper prioritization.
I first started noticing this when playing Assassin’s Creed: Origins, but later in Odyssey, and eventually in any game with sufficient CPU utilization. Whenever the CPU would hit 100% the mouse movement would become unreliable and inconsistent. Naturally, this was rather annoying, so I began investigating the issue.
Running a Prime 95 stress test in the background to simulate 100% CPU usage, I would boot up a game, and sure enough, like clockwork, the mouse movement issue would happen. The mouse went from being responsive to barely moving at all in game. Since, I have a Core i5-8400, which is by no means a weak CPU, I began to delve deeper.
After extensive troubleshooting and multiple re-installs, I was able to discover the issue was at least related to two programs/processes: EA’s Origin client and Oculus’ VR services. At first, I simply just ended the tasks to fix the issue, but later I found something far more peculiar.
Raising these processes (Origin.exe and/or OVRRedir.exe) to a HIGH priority fixes the issue. Similarly, setting the process priority to LOW makes the mouse movement issues infinitely worse, to the point the mouse is almost paralyzed. That’s right, actually demanding more CPU resources from these programs makes the mouse immediately responsive, and lessening their load on the CPU makes it worse. That’s bass-ackwards. Moreover, both of these programs are barely even sipping on the CPU when the issue occurs and totally unrelated to the game being played (in the case of the video documenting the issue, Shadow of the Tomb Raider).
But it get’s more weird: I went through the same procedure on two older quad core CPUs (Ivy Bridge and Haswell) and couldn’t get the issue to occur. Origin and Oculus no longer have any affect on mouse movement. In fact, on these older CPUs, the mouse movement is fine all the time, even at 100% CPU usage, just like it should be. In fact, even the games as a whole felt smoother at 100% CPU. The second I switch back to the 6-core Coffee Lake machine, the issue would happen. That is why I believe the issue is less about the particular programs/processes and more an issue related to some kind of resource management problem with Windows 10 and Coffee Lake CPUs. I could be wrong, but that’s the current conjecture.
I can consistently reproduce the issue on clean installs of Windows 10, across multiple motherboards, and multiple mice all with the latest BIOS and firmware, and all drivers updated. All PC performance vitals are good when the issue occurs (temps, CPU, GPU, RAM, etc) with the exception of the CPU which is of course at 100% to reproduce the issue.
I’m sharing this with the hope that someone can shed some light on the issue, and also because it is eerily similar to your recent video on AMD High-Core-Count Performance Regression. If anyone can solve this mystery, it’s you guys. Thanks in advance.
Specs:
Intel Core i5-8400 @ Stock
G.Skill 16 GBs RAM @ 3200 Mhz
Gigabyte Nvidia Geforce 1080 8GB
Gigabyte Aorus Z390 Pro Wifi
500GB Samsung 960 Evo Nvme @ PCIe X4
500GB Samsung 860 Evo SATA @ 6Gbs/s
Logitech G502
OS: Windows 10 64 Bit Home
Power Plan: High Performance