Question Options for Intel-based Z790 Board that prefer USB Port direct to CPU?

[HarryDrews]

Hello SIRS!!

I recently built a gaming PC, and noticed that I experience (what feel like) differing latency on Scuf controller, depending on which USB port I use AND how many of the other USB ports are occupied.

I've recently discovered that all of my USB Ports go through the chipset instead of directly to the CPU, which adds another "hop", and with it, latency. However, I'm brand new to PCs, so I don't know where a resolution would start.

So my question is - what options do I have with my motherboard if my goal is to minimize latency for at least one high-polling peripheral (either 8khz mouse, or Scuf Controller)?

My immediate thought is USB 2.0 expansion direct to the CPU, but I'm unsure if my motherboard can even do that.

Specs below. Any thoughts, guidance, or chim-in is GREATLY appreciated : )

Specs:
- Intel i7 14700k
- MSI Pro Z790-P
- 4080 Super

Back-facing Ports listed:
∙ 2x USB 3.2 Gen 1 5Gbps Type-A ports (From Z790 chipset)
∙ 1x USB 3.2 Gen 2 10Gbps Type-A port (From Z790 chipset)
∙ 1x USB 3.2 Gen 2x2 20Gbps Type-C port (From Z790 chipset)
∙ 4x USB 2.0 Type-A ports (From Z790 chipset)

MSI MANUAL:
https://download.msi.com/archive/mnu_ex ... -PWIFI.pdf

 

[bill001g]

Not going to find any I suspect. The cpu chip itself has no ability to talk to USB. Now I guess you could look for a USB PCIE board and plug it into one of the slots on the motherboard that directly connects to the CPU. On most motherboards this will be the slot that is used for the video card or if there are multiple cpu connected slots you will cut your bandwidth to the video card slot.

I strongly suspect you have some software issue rather than a hardware issue.

You have to read what you wrote and know what in means. A mouse with a 8khz poll rate is kinda the same as saying it is 8kbits. You can get 1gbit ethernet cards that run on almost any USB port and even 10gbit ethernet adapters on 3.2.

These usb port just yawn when they see the requirements your mouse has.

 

[HarryDrews]

You have to read what you wrote and know what in means. A mouse with a 8khz poll rate is kinda the same as saying it is 8kbits. You can get 1gbit ethernet cards that run on almost any USB port and even 10gbit ethernet adapters on 3.2.

These usb port just yawn when they see the requirements your mouse has.

That makes sense. I'm sure my Scuf controller is a similar, light wisp in the wind for what USB 2.0 port can handle.

If my bro-science serves me, would there be any reason for why my controller seemingly has more latency when other USB ports are being occupied?

And, what would you recommend for optimizing software to reduce latency on my peripheral? I've seen a lot of debloating/optimizing guides but many say they're bologna hype.

Thank you for responding.. I'm loving PCs but I've been going down a rabbit hole.

 

[Eximo]

https://i0.wp.com/glennsqlperforman...Z790-Chipset-Diagram.png?resize=768,865&ssl=1

If you haven't already, update the BIOS for the motherboard and grab the latest drivers. Could easily just be something a little off that has already been taken care of.

You can also seek out the latest drivers from the USB controller manufacturer. In this case likely Intel, but they may have a driver newer than the one offered by MSI. Though you are technically in untested territory at that point.

Interestingly my USB driver on this laptop is from Jan 2024, which is more recent than I was expecting. Dell actually keeping it up to date for once.

 

[bill001g]

I would get one of the software things that test controller mouse latency. I have not used these in a long time.....they quickly showed me it is a user error...finger don't work as fast as you get older.

If you were running disks off USB ports maybe you could overload one but not with simple user i/o peripherals

 

[vMax]

Try Latencymon to see whether you have an issue and where the issue might be from a latency perspective. There was a specific windows based issue and it may just be that you need to do a driver update as this seems to be an odd issue. Definitly update the BIOS to the latest version. The MSI Z790 boards are good though the one you have is the P with the A version being a lot better. I have a similar setup with a MSI Z790 board but no issues, I run my mouse and keyboard of a hub as all my usb ports are minimum 5gbps and 10gbps.

 

[HarryDrews]

Try Latencymon to see whether you have an issue and where the issue might be from a latency perspective. There was a specific windows based issue and it may just be that you need to do a driver update as this seems to be an odd issue. Definitly update the BIOS to the latest version. The MSI Z790 boards are good though the one you have is the P with the A version being a lot better. I have a similar setup with a MSI Z790 board but no issues, I run my mouse and keyboard of a hub as all my usb ports are minimum 5gbps and 10gbps.

Interesting. I installed LatencyMon, and will post some before/after data once I'm done debloating.

Of the USB ports that I have, which do you recommend using? I believe the USB 2.0 is closest to "Intel Extensible USB Root"
∙ 2x USB 3.2 Gen 1 5Gbps Type-A ports (From Z790 chipset)
∙ 1x USB 3.2 Gen 2 10Gbps Type-A port (From Z790 chipset)
∙ 1x USB 3.2 Gen 2x2 20Gbps Type-C port (From Z790 chipset)
∙ 4x USB 2.0 Type-A ports (From Z790 chipset)

 

[hotaru.hino]

Motherboard manufacturers tend to split the ports between USB controllers built in the chipset, either for cost reasons or because between the other I/O, that's how they could get more ports. I don't know if it's actual rule, but allegedly each pair of USB ports on the rear are tied to a USB controller, with USB-C being a wildcard.

So if you want the best chance for a USB device to have the best latency to the system, it should be the only thing connected to one of the pairs.

 

[bill001g]

You can post your results by trying different USB ports. I seriously doubt you are going to see any difference.

This is one of those things where you are worrying about something that only mathematically exists it does not affect real world applications.

You are concern about stuff that would say be related to the speed data travels in copper traces on a motherboard. You can technically say a longer trace takes more time but when you really look at it how much difference is there really if the trace is 5mm shorter when the data travels at 2/3 the speed of light. Can you even calculate how small a number that is going to be.

This is like saying your mouse has a 2ms latency the extra distance on the motherboard might add .000001 ms can you actually detect that. Even if it was a full 1ms could you even detect that without some software testing tool.

 

[vMax]

Interesting. I installed LatencyMon, and will post some before/after data once I'm done debloating.

Of the USB ports that I have, which do you recommend using? I believe the USB 2.0 is closest to "Intel Extensible USB Root"
∙ 2x USB 3.2 Gen 1 5Gbps Type-A ports (From Z790 chipset)
∙ 1x USB 3.2 Gen 2 10Gbps Type-A port (From Z790 chipset)
∙ 1x USB 3.2 Gen 2x2 20Gbps Type-C port (From Z790 chipset)
∙ 4x USB 2.0 Type-A ports (From Z790 chipset)

Usually the USB 2.0 type A ports tend to be best for mouse and keyboard...Test all 4 seperatly and then move to the Gen 1 5Gbps port.