This was more difficult to find and more confusing than I anticipated. I have a new MBP M2 Max. I want to replace my current desktop PC with it.
I use 3 monitors, 2xHD monitors that only have HDMI ports on them, and 1 old 2560x1600 DVI monitor. I want to buy a dock so I can easily plug the laptop in to as few things as possible, ideally even only plugging it in to one thing if possible. I have found USB-C to to DVI-dual link connectors online and I know one can buy USB-C to HDMI adaptors (I’m unclear if I can get TB4 to HDMI adaptors). I also use one of the old apple USB keyboards that had a USB 1.0 hub on it for connecting a mouse which I would definitely want connected via a dock in conjunction with the monitors and also speakers connected via 3.5mm jack. I want a dock specifically so that as soon as I plug the laptop in, it functions just like using a desktop and I’m not needing to hook each of these things up individually every time I’d be operating the laptop in a closed configuration most if not all of the time when at home at my desk.
Ideally then I could find a dock that will connect to a TB4 port and will have either HDMI or Displayport ports on it that I can connect the monitors to, or additional TB4 ports that I can hook the monitors up to via adaptors. I’d also ideally then be able to hook up some fast storage to such a dock but that’s where I get a bit confused about how the bandwidth situation works and how resources are divided up and how that influences what dock to buy. This is a slightly less important requirement because I probably won’t be hooking up storage all the time and when I do, I don’t mind using up one of the remaining TB4 ports on the MBP for that, but for convenience sake it sure would be nice if I could hook a USB-C gen 2 drive or TB4 drive to the dock while it’s connected to the 3 monitors, just don’t know how possible that is.
Something else that’s confusing me is, I was looking at the Sonnet Echo 11 and it was mentioned somewhere in a tech specs document that you could plug monitors in to it’s TB4 ports with active adaptors. I remember having to make such a distinction a long time ago back when DVI was still a thing, that in order to use the full resolution of a DVI device one needed an active vs passive adaptor to actively convert the signal and that the active variant was much more expensive and contained powered circuitry. This irks me, because if that’s what they’re talking about here with HDMI to USB-C connectors plugging in to those TB4 ports on the dock it’d be very disappointing because I thought if one shells out a bunch of cash for a fairly chonky dock that it would take care of any such conversions and the idea of having to spend a whole bunch more money to get the “active” adaptors for each monitor in order to connect to the dock that I was hoping would be my adaptor is a bit galling.
As far as I know, there are no TB4 -> HDMI adapters, but almost all USB-C -> HDMI adapters are active adapters, so they should work on the Echo 11 (they work on my Lenovo TB4 dock’s TB port, so I’d assume they work on the Sonnet as well). The difference between active and passive USB-C -> HDMI adapters is that active adapters use DisplayPort alternate mode and passive ones use HDMI alternate mode.
If I understand the specs correctly, you can only use two monitors connected to the Echo 11 with an M2 Max system, so you’d need to plug an additional USB-C adapter for your third monitor into your MBP.
You should still have enough bandwidth on the TB4 port that your storage devices aren’t slowed down noticeably - if my calculation is correct, the two monitors shouldn’t need more than a quarter of the available bandwidth.
Yeh I thought that might be the case with the 3 monitor situation. That’s no biggie, i only use the 3rd monitor sometimes anyway. I’m confused by then calculations in Wolfram Alpha though, the resulting answer is expressed in bitpixels per second so I don’t really know how to convert that. It does spring an interesting question to mind though. Do these thunderbolt and/or modern USB-C docks work a bit better than the USB 3.0 hubs of old? Because my experience with those was that every device plugged in to them was allocated an equal portion of bandwidth regardless of how much it actually needed so if you plugged a USB1.0 keyboard in, and a USB3.0 hard drive, they’d each have a maximum 2.5Gbps, despite the keyboard needing absolutely nowhere near that and the hard drive quite possibly wanting that and more. The way you describe calculating the bandwidth requirements sounds a bit smarter because it seems like you’re figuring out the most bandwidth a given thing like a monitor might want and how much something like a hard drive might want and comparing against the maximum throughput of the TB4 port that the dock is connected to which would be way better than the USB3.0 hub situation I was describing.
So do you think an echo 11 is a good choice then? I’ve been looking in to the caldigit TS4 and it looks perfect but just eye wateringly expensive and also very hard to come by here in Australia. It looks like the TS3 is more available and a little less painful on the hip pocket so I guess it’s an option.
On any USB hub that works correctly, bandwidth is only assigned to devices that actually use it - that means that a USB keyboard will not use more than a few kilobits per second and won’t slow down a fast device on the same hub.
The calculation has a result of 8.884 gigabits per second, so there should be about 31 Gbps left over for any other devices.
I think the Echo 11 is probably a good choice - there are some less expensive TB3/TB4 docks, but they seem to be designed for Windows devices only so there might be some driver issues on macOS. I have no idea how expensive the TS3 is in Australia, but in Germany it costs 50% more than the Echo 11 and I don’t think it’s actually 50% better.