That being true.
However, most people only have one PCIe card: the GPU and nothing else. It’s very rare you don’t have a x1 slot (8000Hz mouse only needs a tiny x1 slot).
If you’re a pro user with a video capture card and a 10 gigabit Ethernet card, and have a gigantic heatsink blocking one PCIe slot too, read on — see solutions below:
Also, hacks exist.
(A) x1 PCIe riser ribbon extension cables are available for purchase too — can also allow you to use a PCIe USB card externally or in a slotless area of your computer. You can fit some of those x1 PCIe slot-extension cables sometimes in the obstructed spare slot underneath a triple-width GPU (or overhanging gigantic heatsink etc), snake the ribbon cable under your GPU to open space, and dangle the USB port card in open air outside the rear of the PC, if absolutely necessary. Clever, huh?
* Or build a tiny black box for it and tape the black box to a different part of your PC. Or even just wrap the USB3 card in black duct tape to protect the circuit board from shorting against the metal of your computer case. Be creative in how you protect the bare USB card.
Google “x1 PCIe riser cable” on Amazon or ebay. PCIe USB cards don’t need more than x1 slot to support an 8000Hz mouse, and x1 is less error-critical than x16, and can tolerate a short extension cable, usually. Heck, try two — including one shorter — a different cable may be higher quality, since riser cables are sometimes lottery. Keep it as short as you feasibly can. Some are lower-profile and some PCIe connectors have 90-degree turns. Find a custom riser cable that fits where you need it to fit. You probably only need 4 or 6 inches.
(B) Wait, there’s more.
If your motherboard has a Thunderbolt port (not just a USB-C port), use a true real Thunderbolt hub and plug your mouse into that. Just don’t plug anything else into that thunderbolt hub, so 100% of that Thunderbolt port is dedicated to the 8000 Hz mouse. A bit overkill, but Thunderbolt has pretty low latency compared to USB, and you’re simply pushing a dedicated USB chip into the external Thunderbolt hub.
(C) No, I’m still not finished yet.
Does your motherboard have a USB-C port? Sometimes it’s on its own dedicated chip. Use a USB-C-to-USB-A adaptor. It’s not as good as Thunderbolt, but it may bypass a crappy USB-A port tree.
(D) Wait, I’ve got yet more too.
Some NVIDIA GPUs has one of their multiple video outputs in the form of a USB-C connector instead of a DisplayPort connector. You can connect regular USB accessories to these ports! Yep. One of the video ports is sometimes also a USB-C port on your GPU. It’s also fair game for an 8000 Hz mouse too.
(E) Um, I’m not finished yet.
Do you have a spare USB2 or USB3 motherboard header? Check your motherboard manual, there may be a big surprise of extra unused USB ports on your motherboard that is idling on its own unused dedicated circuitry. Often they are for front ports or top-surface ports, but many cases have fewer USB ports than USB headers on the motherboard.
If you’re willing to be creative, you can usually workaround an 8000 Hz issue without a motherboard replacement. It’s fortunately very rare that you can’t do any of these creative workarounds. Some of these are still a pain, but less painful than a motherboard replacement.
There’s usually overlooked low lying apples. Check these unexpected places.
