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Discussion Starter · #1 ·
I recently learned about interrupt priority control:
https://www.overclock.net/forum/375-mice/1550666-usb-polling-precision.html
In regedit you can enter device/driver to which you want assign irq priority. This helps a lot, supposedly you should assign cmos, or gpu first. You can assign multiple values 1,2,3 which set order of interrupts being prioritized... I tested it and there are is drastically lower input lag, with any of permutation i tried. But still not sure what i wanna use. I have currently cmos first 1, than gpu 2 and than ehci 3 (usb mouse). My gaming monitor died and i am currently on va panel so this helps a lot! I want to know more, something that would allow me infer best order for interrupt priority. I am not hardware, or driver expert and i didn't google anything except that i said. Anyone have some good source for assigning interrupt priority control to devices drivers ?
 

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I recently learned about interrupt priority control:
https://www.overclock.net/forum/375-mice/1550666-usb-polling-precision.html
In regedit you can enter device/driver to which you want assign irq priority. This helps a lot, supposedly you should assign cmos, or gpu first. You can assign multiple values 1,2,3 which set order of interrupts being prioritized... I tested it and there are is drastically lower input lag, with any of permutation i tried. But still not sure what i wanna use. I have currently cmos first 1, than gpu 2 and than ehci 3 (usb mouse). My gaming monitor died and i am currently on va panel so this helps a lot! I want to know more, something that would allow me infer best order for interrupt priority. I am not hardware, or driver expert and i didn't google anything except that i said. Anyone have some good source for assigning interrupt priority control to devices drivers ?
Not sure if i can help you as i can't even figure out which of the 2 AMD 3.10 controllers is my mouse using.
However you can use this simple tool https://forums.guru3d.com/threads/windows-line-based-vs-message-signaled-based-interrupts.378044/ to set usb controllers to "High" interrupt priority and enjoy an input lag reduction.
 

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Anyone remember when interrupts were set with jumpers on the card? The dreaded IRQ conflict error message.
 

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Anyone remember when interrupts were set with jumpers on the card? The dreaded IRQ conflict error message.
iirc the jumpers weren't that bad, it was going into WFW 3.1 and assigning that and the COM ports that caused my hair loss.
 

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how are you testing your latency?

also, is this an Windows(AMD) thing? as stated above, i haven't heard this discussed since it was a physical thing when I was quite literally a wee lad.

I'm a bit lost why you didn't ask in the thread where you learned of this. It should be a megathread if the info provided is correct at any measure.
 

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Discussion Starter · #6 · (Edited)
I have nvidia, but has to do nothing with gpu brand, it is set it in windows under:
Computer\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\PriorityControl

I don't have 1000fps camera, but i can tell even 6ms, tested myself with blurbusters inputlag ab test. After giving priority to cmos, ehci and gpu, mouse seems much more responsive.
I read this is residue from windowsNT, but i can tell difference, when using this setting so it seems works. I am just not in what order i want to set my priorities. Curently have cmos 1, ehci 2, gpu 3. Not sure about system timer.

I have also 2 programs to test it with, i yet test it when my mouse polls being handled, currently 80us, during maximum polling rate.
From this topic on overclockers i listed in my first post, you can tell down to 50us supposedly, it is not strange and combined with others. Plus over time latency stacks and you can really feel these micro latencies on mouse movement.
 

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I have nvidia, but has to do nothing with gpu brand, it is set it in windows under:
Computer\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\PriorityControl

I don't have 1000fps camera, but i can tell even 6ms, tested myself with blurbusters inputlag ab test. After giving priority to cmos, ehci and gpu, mouse seems much more responsive.
I read this is residue from windowsNT, but i can tell difference, when using this setting so it seems works. I am just not in what order i want to set my priorities. Curently have cmos 1, ehci 2, gpu 3. Not sure about system timer.

I have also 2 programs to test it with, i yet test it when my mouse polls being handled, currently 80us, during maximum polling rate.
From this topic on overclockers i listed in my first post, you can tell down to 50us supposedly, it is not strange and combined with others. Plus over time latency stacks and you can really feel these micro latencies on mouse movement.

how did you priority those?

And what is your Win32PrioritySeparation Data Value?

http://recoverymonkey.org/2007/08/1...-quanta-in-windows-and-a-bit-about-unixlinux/
https://superuser.com/questions/456...oards-less-responsive-due-to-narrow-irq-range
 
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