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Input Lag - USB Ports connected to CPU

Posted: 11 Feb 2024, 15:55
by Janbobo28
Good evening,

I have a MSI B660 Mortar DDR4 Mainboard and want to put my gaming mouse + keyboard into the CPU-connected USB-Ports but just can't figure out which ones they are because it's not listed in the Manual and tools like USB Device Tree Viewer or HWinfo064 aren't really helpful either. According to the tools I can't even see my motherboard-chip USB-host controller.

Rest of my PC specs are:

- RTX 3060
- i5 12500
- 32 GB DDR4 RAM (CL14)
- 1 TB M.2 SSD
- Logitech G502 lightspeed Mouse
- HyperX Allow Elite 2 Keyboard
- LG-27 GP850-B Monitor

Not sure if a USB-Card can make sense in that case.

Re: Input Lag - USB Ports connected to CPU

Posted: 11 Feb 2024, 21:08
by andreeeeee-
This distinction applies only to Ryzen, that's why your mobo manual doesn't list it.

Cool video explaining it:
https://youtu.be/88IOcFE4yho

Re: Input Lag - USB Ports connected to CPU

Posted: 13 Feb 2024, 18:57
by Janbobo28
andreeeeee- wrote:
11 Feb 2024, 21:08
This distinction applies only to Ryzen, that's why your mobo manual doesn't list it.
Thanks for the reply, does that mean Intel doesn't even have a CPU-connected USB-port at all because in one video someone said it you should put your usb devices into the Intel-USB-Host controller.

Re: Input Lag - USB Ports connected to CPU

Posted: 13 Feb 2024, 21:00
by andreeeeee-
Janbobo28 wrote:
13 Feb 2024, 18:57
andreeeeee- wrote:
11 Feb 2024, 21:08
This distinction applies only to Ryzen, that's why your mobo manual doesn't list it.
Thanks for the reply, does that mean Intel doesn't even have a CPU-connected USB-port at all because in one video someone said it you should put your usb devices into the Intel-USB-Host controller.
Yes

The video you mention may be talking about "Intel USB 3.0 eXtensible Host Controller" (xHCI) driver in contrast to the "Enhanced Host Controller Interface (EHCI)" (USB 2.0).

I don't know the context, but maybe they are saying on that video that you should connect your usb devices to USB ports 3.0, not 2.0

Re: Input Lag - USB Ports connected to CPU

Posted: 27 Mar 2024, 11:02
by FPSMaster
Hey, the Chipset USB connectors should be decent in handling your mouse and keyboard. Just make sure to put your mouse on a different USB controller then your keyboard. You can put your keyboard on a USB 2.0 port and Mouse on a USB 3.0 port.

I actually tested the USB controller latency on my ryzen system with nvidia reflex analyzer. I compared the USB Controller that is connected to the CPU and the one connected to the Chipset. There was no difference in terms of latency. Not even 1ms difference.

But I got slightly better mouse pollingrate graphs on the CPU USB controller.

Re: Input Lag - USB Ports connected to CPU

Posted: 27 Mar 2024, 12:52
by TheKelz
FPSMaster wrote:
27 Mar 2024, 11:02
Hey, the Chipset USB connectors should be decent in handling your mouse and keyboard. Just make sure to put your mouse on a different USB controller then your keyboard. You can put your keyboard on a USB 2.0 port and Mouse on a USB 3.0 port.

I actually tested the USB controller latency on my ryzen system with nvidia reflex analyzer. I compared the USB Controller that is connected to the CPU and the one connected to the Chipset. There was no difference in terms of latency. Not even 1ms difference.

But I got slightly better mouse pollingrate graphs on the CPU USB controller.
Hey there.

Any ways of finding out which USB ports are for CPU on B650 Gigabyte Aorus Elite AX mobo? I've read the manual but can't in the life of me figure it out.

Re: Input Lag - USB Ports connected to CPU

Posted: 27 Mar 2024, 13:13
by FPSMaster
TheKelz wrote:
27 Mar 2024, 12:52
FPSMaster wrote:
27 Mar 2024, 11:02
Hey, the Chipset USB connectors should be decent in handling your mouse and keyboard. Just make sure to put your mouse on a different USB controller then your keyboard. You can put your keyboard on a USB 2.0 port and Mouse on a USB 3.0 port.

I actually tested the USB controller latency on my ryzen system with nvidia reflex analyzer. I compared the USB Controller that is connected to the CPU and the one connected to the Chipset. There was no difference in terms of latency. Not even 1ms difference.

But I got slightly better mouse pollingrate graphs on the CPU USB controller.
Hey there.

Any ways of finding out which USB ports are for CPU on B650 Gigabyte Aorus Elite AX mobo? I've read the manual but can't in the life of me figure it out.
I looked at that manual and indeed, it is pretty confusing. I really don't know why most motherboard producers still don't correctly label these ports.

Anyways, yes there are ways to identify the CPU USB ports.
Download and install HWInfo. Then look under the "PCI Bus" category.
There are these connections called Internal PCIe Bridge to bus "XYZ".
Under that, look for the USB3 XHCI Controller that is labled with the architecture of your CPU. For example, I use a CPU with the architecture Pinnacle Ridge.
So, for me it would show my mouse is connected to the USB Root Hub under "AMD Pinnacle Ridge - USB3 XHCI Controller".

If your mouse wont show up at the CPU controller you just identified, try out every USB port until your mouse shows up there.

Good luck

Re: Input Lag - USB Ports connected to CPU

Posted: 29 Mar 2024, 03:51
by TheKelz
FPSMaster wrote:
27 Mar 2024, 13:13
TheKelz wrote:
27 Mar 2024, 12:52
FPSMaster wrote:
27 Mar 2024, 11:02
Hey, the Chipset USB connectors should be decent in handling your mouse and keyboard. Just make sure to put your mouse on a different USB controller then your keyboard. You can put your keyboard on a USB 2.0 port and Mouse on a USB 3.0 port.

I actually tested the USB controller latency on my ryzen system with nvidia reflex analyzer. I compared the USB Controller that is connected to the CPU and the one connected to the Chipset. There was no difference in terms of latency. Not even 1ms difference.

But I got slightly better mouse pollingrate graphs on the CPU USB controller.
Hey there.

Any ways of finding out which USB ports are for CPU on B650 Gigabyte Aorus Elite AX mobo? I've read the manual but can't in the life of me figure it out.
I looked at that manual and indeed, it is pretty confusing. I really don't know why most motherboard producers still don't correctly label these ports.

Anyways, yes there are ways to identify the CPU USB ports.
Download and install HWInfo. Then look under the "PCI Bus" category.
There are these connections called Internal PCIe Bridge to bus "XYZ".
Under that, look for the USB3 XHCI Controller that is labled with the architecture of your CPU. For example, I use a CPU with the architecture Pinnacle Ridge.
So, for me it would show my mouse is connected to the USB Root Hub under "AMD Pinnacle Ridge - USB3 XHCI Controller".

If your mouse wont show up at the CPU controller you just identified, try out every USB port until your mouse shows up there.

Good luck
Very helpful. Thanks a lot.