# Unsmooth/choppy mouse movements/polling during high cpu usage



## Frs4ken

So I recently got into Apex Legends and I've come across this issue where my mouse inputs are very jittery/choppy while in a busy area or looking at a large of the map. I'm suspecting its related to high cpu usage and although naturally this only happens in real BR matches I've managed to recreate it in testing range by using prime95 on 4 cores out of 16(9900k)

Description of the issue:
Instability of mouse input processing or frametime spikes *NOT VISIBLE ON FRAMETIME GRAPHS* caused by mouse interrupts. This leads to a choppiness when panning and tracking enemies. 

Here is some 120FPS footage of me comparing mouse inputs to controller inputs. 
download the video to view it in 120fps.
-Controller is perfectly smooth while using the mouse results in jitter. 
-look at the buttons to see which input I am using. 

Here's some footage on a random part of the map. There is not even a lot of activity going on here but the stuttering is still present.
The stutter is much worse when there are multiple teams fighting
in game example.mkv

I managed to recreate this issue in the test range by simulating high cpu usage with prime95
120fps cap.mp4


Pretty obvious that the mouse input is laggy compared to controller because the game only processes the position of the joystick at 125hz. Strafing with the keyboard is pretty smooth too as it should be. Only when I move the mouse it becomes laggy

Heres some footage on youtube since the jitters are visible EVEN on 60fps. The 120fps videos show it better though.
Focus on the crosshair, the stutters make the pipe and weapons "vibrate" while doing this type of maneuver.
LOOK AT THE BUTTON HINTS TO SEE WHICH INPUT I AM USING










Things I've tried (main rig) 9900k, gtx 1080
stock windows 20h2 
stock windows 21h2
stock windows 7 sp1
125hz, 500hz, 1000hz polling
different usb ports (usb 2, usb 3, front panel)
all devices unplugged except mouse
different mouse, different keyboard, different mousepad
180fps cap, 160fps cap, 140fps cap, 120hz cap. It seems like is reduced the I go but it is definitely still there. 
r5apex low priority, high priority
mouse interrupt cpu affinity
different nvidia drivers
cpu underclock
cpu overclock
cpu stock (stock bios)
hyperthreading on, off
different monitor
entirely different rig (9600k, 1650 super)

At this point I just think its the game but how come no one else has noticed it? 
I really would appreciate it if someone could try this out on their setup. 
If you want to try it out just go to a busy area in the map (might have to try multiple times as it seems very random on which areas of the maps it happens) and do the same movement I am doing in the video footage.

You can also go to testing range and run large fft's on 4+ cores
confirmed that the stutter only happens on 4+ atleast on 9900k and 9600k



Since I've tried pretty much everything I suspect it's just due to a bug in the game engine similarly to how the frame pacing in this game breaks when its running at 200+ FPS, but then again how isn't this on the front page of r/apexlegends?
I've wasted lots of hours trying to fix this and would appreciate if any apex players on this forum could try this out so I know if its just the engine being bad or something wrong with my setup


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## EastCoast

Try changing USB driver from core 0 to another physical core using an ms app called Interrupt Affinity Policy Tool . You can use latencymon's cpu tab to monitor a file called wdf01000.sys. You won't see it at default win10 scheduler because everything is lumped up on core 0. You want to move it to another physical core. When using Latencymon all even numbered cores are physical cores if you are using hyperthreading or SMT.

Watch this video and pay attention on how to identify Location of the PCI bus that your usb uses. For that you will use Device Manager. The video will explain it all. You have to pay attention because it's pretty advanced. But it does work. Now it won't address the root cause of your problem. Because only you know what you did to win10, bios, etc.

If anything I would suggest you set your bios to default settings 1st. Then test mouse movement. In any case below is the video.


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