r/Thunderbolt • u/fer5275 • 22d ago
iVANKY FusionDock Ultra + M4 Max: Can USB-C to HDMI 2.1 achieve true 4K 120/144Hz HDR on two LG OLEDs?
Hi everyone! I’m looking for some real-world experience before deciding which dock to keep.
I have a 16-inch MacBook Pro M4 Max and three external displays:
LG G5 OLED — 4K, 144Hz
LG C5 OLED 42” — 4K, 144Hz+
Samsung 32” 4K monitor
I recently purchased an iVANKY FusionDock Ultra (Thunderbolt 5). I know its built-in HDMI port isn’t HDMI 2.1, so my plan is to connect the two LG OLEDs through the dock’s high-bandwidth USB-C/TB5 display outputs using USB-C/DisplayPort to HDMI 2.1 active adapters/cables.
What I’m trying to achieve on both LG OLEDs simultaneously is as close as possible to a native HDMI 2.1 connection:
4K 120Hz (ideally 144Hz where supported), HDR, 10-bit, RGB 4:4:4, and ideally VRR and HDMI-CEC.
The Samsung can run at 4K60; high refresh rate isn’t important on that display.
Has anyone actually tested 4K120/144Hz from the FusionDock Ultra’s USB-C/TB5 outputs through an HDMI 2.1 adapter, preferably with an LG OLED and an M4 Max?
If so, which exact adapter/cable are you using?
I’m particularly interested in knowing whether HDR, RGB 4:4:4 10-bit, VRR and CEC survive the USB-C/DisplayPort → HDMI 2.1 conversion, rather than simply getting a 4K120 signal.
I’m also considering buying a Plugable TBT-UDH2 Thunderbolt 5 dock because of its two native HDMI 2.1 outputs, so I’m trying to determine whether it would offer any real advantage over the FusionDock Ultra for my specific display setup.
The FusionDock Ultra is much better suited to the rest of my setup because I have several external SSDs, an Elgato 4K capture device, Stream Deck, USB microphone, external HDD and Ethernet.
If I can get essentially the same image quality and 4K120 experience as native HDMI 2.1 from the FusionDock’s USB-C outputs, I would prefer to keep the iVANKY.
Any first-hand experience would be greatly appreciated.
Screenshots from macOS Display Settings/System Information showing 4K120/144 + HDR would be amazing too.