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Also note that if you have a laptop that supports Thunderbolt, you need a docking station that supports Thunderbolt. If you have a laptop that supports Alternat

Also note that if you have a laptop that supports Thunderbolt, you need a docking station that supports Thunderbolt. If you have a laptop that supports Alternate Video Mode, you need a docking station that supports Alternate Video Mode. AFAIK no laptop supports both modes, and very, very few docking station supports both. (you'll usually get reduced features if you have a mismatch; for instance, you'll get just one monitor, or two monitors at low resolution, or no video out at all, just the additional USB/ethernet ports) My work laptop has Thunderbolt, my personal laptop does not. So this is an issue for me. I have a Plugable TBT-UDZ, which is one of relatively few docking stations that supports both. I can therefore use two 2560x1440 60Hz displays through either laptop. This isn't without issue. My work PC (Windows) will every other week or so BSOD when connected to it, but, well, it's Windows. My personal personal computer (linux) will not crash, but every other week or so will simply refuse to recognize the docking station. So I have to unplug the docking station and plug it back in. It's annoying, but not the end of the world. I believe these two issues are the same issue, but I haven't bothered to confirm that. I don't have a Mac to try it on. https://plugable.com/products/tbt3-udz https://plugable.com/products/tbt3-udz

realityking 5y ago
AFAIK all MacS that support Thunderbolt also support DisplayPort alt mode. Is that different on the PC side? That’d be quite surprising. What Macs don’t support ist DisplayPort MST. So the only way to power two monitors with one adapter would indeed be Thunderbolt.
lstamour 5y ago
Personal anecdote but I’ve found many thunderbolt or USB-based displays seem to suffer from the plug and unplug issue. I’ve had the most success historically using the DisplayPort over USB-C spec with an 8K-compatible cable (that means it’s the latest spec version): https://www.displayport.org/displayport-over-usb-c/ https://www.displayport.org/displayport-over-usb-c/ Outside of that… some USB-C based docks likely use the above standard internally, plus USB-C spec support for driverless Ethernet, hubs, etc. That said, there’s always something to complain about with these accessories and cables, it seems…
satrday 5y ago
The thunderbolt protocol is backwards compatible, so a USB-C dock should work when plugged into a laptop’s Thunderbolt port. CalDigit has a USB-C dock and one of the biggest “features” they push is its compatibility.
timmaxw 5y ago
> AFAIK no laptop supports both modes Are you sure? From what I've seen, it seems common for laptops to support the combination of Thunderbolt and DisplayPort Alternate Mode. (Both my MacBook and my Thinkpad T480s have ports like this.)
microtonal 5y ago
Also note that if you have a laptop that supports Thunderbolt, you need a docking station that supports Thunderbolt. If you have a laptop that supports Alternate Video Mode, you need a docking station that supports Alternate Video Mode. AFAIK no laptop supports both modes, and very, very few docking station supports both. As far as I understand, Thunderbolt 3 needs to support 4x PCI Express 3.0, DisplayPort 1.2, and USB 3.1 Gen 2 [1] (slides 8, 10-15). And Intel advertises that their Thunderbolt 3 controllers can switch to DisplayPort-only alt-mode [1]. All the Thunderbolt 3/4 Macs that I have had (Intel and M1) definitely supported DP alt-mode (I hooked up a 4k@60Hz that way for years) and also USB-C docks that allocate lanes for DP alt-mode and USB 3.1. Obviously, Thunderbolt docks also work. [1] https://www.thunderbolttechnology.net/sites/default/files/IDFSF15_HSTS004_100a_1.pdf https://www.thunderbolttechnology.net/sites/default/files/ID... [2] https://www.thunderbolttechnology.net/sites/default/files/Thunderbolt3_TechBrief_FINAL.pdf https://www.thunderbolttechnology.net/sites/default/files/Th....
torginus 5y ago
My work Thinkpad P52 and Macbook Pro M1 both support TB and DP alt mode.

realityking 5y ago

AFAIK all MacS that support Thunderbolt also support DisplayPort alt mode. Is that different on the PC side? That’d be quite surprising. What Macs don’t support ist DisplayPort MST. So the only way to power two monitors with one adapter would indeed be Thunderbolt.

lstamour 5y ago

Personal anecdote but I’ve found many thunderbolt or USB-based displays seem to suffer from the plug and unplug issue. I’ve had the most success historically using the DisplayPort over USB-C spec with an 8K-compatible cable (that means it’s the latest spec version): https://www.displayport.org/displayport-over-usb-c/ https://www.displayport.org/displayport-over-usb-c/ Outside of that… some USB-C based docks likely use the above standard internally, plus USB-C spec support for driverless Ethernet, hubs, etc. That said, there’s always something to complain about with these accessories and cables, it seems…

satrday 5y ago

The thunderbolt protocol is backwards compatible, so a USB-C dock should work when plugged into a laptop’s Thunderbolt port. CalDigit has a USB-C dock and one of the biggest “features” they push is its compatibility.

timmaxw 5y ago

> AFAIK no laptop supports both modes Are you sure? From what I've seen, it seems common for laptops to support the combination of Thunderbolt and DisplayPort Alternate Mode. (Both my MacBook and my Thinkpad T480s have ports like this.)

microtonal 5y ago

Also note that if you have a laptop that supports Thunderbolt, you need a docking station that supports Thunderbolt. If you have a laptop that supports Alternate Video Mode, you need a docking station that supports Alternate Video Mode. AFAIK no laptop supports both modes, and very, very few docking station supports both. As far as I understand, Thunderbolt 3 needs to support 4x PCI Express 3.0, DisplayPort 1.2, and USB 3.1 Gen 2 [1] (slides 8, 10-15). And Intel advertises that their Thunderbolt 3 controllers can switch to DisplayPort-only alt-mode [1]. All the Thunderbolt 3/4 Macs that I have had (Intel and M1) definitely supported DP alt-mode (I hooked up a 4k@60Hz that way for years) and also USB-C docks that allocate lanes for DP alt-mode and USB 3.1. Obviously, Thunderbolt docks also work. [1] https://www.thunderbolttechnology.net/sites/default/files/IDFSF15_HSTS004_100a_1.pdf https://www.thunderbolttechnology.net/sites/default/files/ID... [2] https://www.thunderbolttechnology.net/sites/default/files/Thunderbolt3_TechBrief_FINAL.pdf https://www.thunderbolttechnology.net/sites/default/files/Th....

torginus 5y ago

My work Thinkpad P52 and Macbook Pro M1 both support TB and DP alt mode.