Hi Casey, by any chance is the Z490 Vision D front panel (F_U32C) USB Type-C capable of "USB 3.2 Gen 2x2 20Mbps" cause I get 10Mbps on SS01, reverse the plug, get 10Mbps on SS02 with a USB 3.2 Gen 2 device ? It appears both 10Mbps ports are wired to/from the MB Type-E header to Type-C connectors ? This appears very similar to the same location Z590 chipset port (ie. Z590 Vision D block diagram) that shows it as a 1 x USB 3.2 Gen 2x2. Via PCH, not RKL CPU.
I recently upgraded my OC 0.7.1 BigSur from a 10th Gen CPU to a i7-11700K (plus BIOS F20 for RKL support) and amazingly, it flies in default BIOS mode and is just as stable as any MB ! Yeah it can pull 250W and needed an extra cpu cooler fan. Plus after much pain I found a workaround for the RKL XMP BIOS mess - I have 3200MHz CL16 4x16GB ADATA mem, so every time you screw things up you MUST clear CMOS, Load BIOS Defaults, select XMP Profile 2, select DDR4-3600 (yeap not a typo - to get a magic system memory multiplier that works), can set "Gear 1 or leave as Auto, same result", "do nothing else !" then Save BIOS & reboot - Bingo, "Gear 1" @ 3,273Mhz Memory Clock (macOS shows a bit higher ?). Also the RKL CPU connected PCIe 4.0 NVMe M.2 works - tested with Gen3 NVMe - nice 3500/3000MB read/write with ADATA SX8200 Pro. Yeah no more PCH traffic jams
I used Windows HwInfo to check available and used link speeds - can't find a Mac equiv. The GPU and adjacent PCIe X8 slot are PCIe 4.0. Even the RKL Xe iGPU works in 'VGA' (HD) mode out-of-the-box under Catalina & BigSur - no config.plist additions. Great backup if you just sold your dGPU - no acceleration but performance is quite useable, except GPU intensive games or apps.
BUT I still have the same confusion (F5 or F20 BIOS) with the rear Type-C ports (shared for Thunderbolt & USB). Somedays I can hotplug in & out USB 3.2 Gen 1 or 2 devices in and they work, other days they only run at USB 2. If I disable Thunderbolt in BIOS I completely loose the TR XHC/USB3 host, but always have USB2 via the Chipset XHC controller. Thunderbolt 3 devices work flawlessly - even mixed mode 1 x TB3 device and 1 x USB 3.2 device.
I'd love to know if a USB4/Thunderbolt 4 hub works with the original GC Z490 Vision D NVM-50 thunderbolt chip firmware - I already custom flashed your modded NVM-50 and it doesn't support the hubs ? I preferred not to risk re-flashing to test
On a brighter side, it appears Gigabyte designed these MBs and wrote the user manual before they knew what Rocket Lake was, so it now seems the Z490 chipset with GC's PCIe switches is a better MB than the Z590 chipset ?
I'll now keep my Z490 Vision D MB a bit longer
. Attached a few system pix that may help others.
Cheers, J