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How to force route USB 2.0 devices off XHCI controller on Z97?


Me being an electronics hobbyist means my machine often have a lot of weird stuff hanging on its USB ports. That results in me running out of USB resources very often under Windows 10.


From a forum post somewhere I have ran across the claim that the XHCI controller in Intel Z97 chipset is bugged: instead of supporting 128 endpoints as specified in USB standards, it supports only 96 endpoints. When I checked the Device Manager under Windows, all my USB devices shows up under the XHCI controller. With all the weird items I have and that bugged chipset implementation I quickly ran out of endpoints on that Intel XHCI controller, thus running out of the resources Windows was being vague about.


I know for sure that through some kernel-level software the USB 2.0 devices can be multiplexed away from the XHCI controller and to the two EHCI controllers on the same chipset. Since I use that machine primarily as a Hackintosh, one of the USB kexts (in macOS a kext is a kernel mode driver) forces that multiplexing to happen, and under macOS with that additional driver I can verify that my USB 1.1 and USB 2.0 peripherals shows up under the EHCI controller while only USB 3.0 devices shows up under the XHCI controller. Intel’s EHCI implementation does not have that lack of endpoint bug.


Is there any way to implement a similar force-non-USB-3.0-devices-off-XHCI patch for Windows?

Workstation 1: Core i7-9700K ~ 2x Corsair Vengeance LPX 16GB DDR4-3000 ~ Gigabyte Z390 UD ~ Sapphire RX 580 8GB ~ WD Black NVMe 1TB ~ WD Black 2TB ~ macOS Big Sur amd64
Workstation 2: 2x Xeon E5-2696v2 ~ 8x Kingston KVR 16GB DDR3-1600 Registered ECC ~ Asus Z9PE-D16 ~ 2x Reference RX 480 8GB ~ WD Black NVMe 1TB ~ WD Green SATA 6TB ~ Windows 10 Pro Workstation amd64
Home server: Xeon E3-1231v3 ~ 2x Samsung 8GB DDR3-1600 Unbuffered ECC ~ Asus P9D-M ~ Broadcom MegaRAID 9271-8iCC ~ Gigabyte 480GB SATA SSD ~ 8x Mixed HDD 2TB ~ 16x Mixed HDD 3TB ~ Proxmox VE amd64

Laptop 1: Dell Latitude 3500 ~ Core i7-8565U ~ NVS 130 ~ 2x Samsung 16GB DDR4-2400 SO-DIMM ~ Samsung 960 Pro 512GB ~ Samsung 850 Evo 1TB ~ Windows 10 Education amd64
Laptop 2: Apple MacBookPro9.2 ~ Core i5-3210M ~ 2x Samsung 8GB DDR3L-1600 SO-DIMM ~ Intel SSD 520 Series 480GB ~ macOS Catalina amd64

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