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Two 4k @ 60 Hz is either Thunderbolt (which is fine for Macs but has a price and I would rather buy like https://www.monoprice.com/product?p_id=38575 https://ww
by chx 7y ago
Two 4k @ 60 Hz is either Thunderbolt (which is fine for Macs but has a price and I would rather buy like https://www.monoprice.com/product?p_id=38575 https://www.monoprice.com/product?p_id=38575 or https://www.monoprice.com/product?p_id=31261 https://www.monoprice.com/product?p_id=31261 instead of a noname company) or DisplayLink which is to be avoided at all costs. This hub is Thunderbolt as can be deciphered from "Does not support MacBook models with single USB-C port" (see https://support.apple.com/en-us/HT201736#usbc https://support.apple.com/en-us/HT201736#usbc ) but the fact I need to decipher what it is a second strike against it. It seems lately Intel has loosened its iron grip on Thunderbolt 3 (after all, it handed the standard over to USB IF) so now everything goes (we see empty M.2 to TB3 enclosures and chaining eGPU boxes both of which were forbidden by Intel prior) but the fact they didn't include the trademarked name makes me go hm.
Finally, it could be a DP 1.4 MST hub but that is very rare (the first USB C to DP 1.4 MST I am aware of was announced at CES 2020 https://plugable.com/2020/01/07/plugables-new-docking-station-and-adatpers-at-ces-2020-raise-the-bar-for-connectivity-power-and-productivity/ https://plugable.com/2020/01/07/plugables-new-docking-statio... and didn't ship yet) and figuring out support will be _very_ interesting. All Intel 14nm laptop CPUs are stuck with DisplayPort 1.2 and then researching which laptops with Radeon / nVidia GPUs run their USB C through those GPUs to provide DP 1.4 will be fun.
Let's put 4k @ 60 (and then 4k @ 30) into the bandwidth calculator: https://linustechtips.com/main/topic/729232-guide-to-display-cables-adapters-v2/?section=calc&H=3840&V=2160&F=60&calculations=show https://linustechtips.com/main/topic/729232-guide-to-display... you can see you need more than what DP 1.2 can provide so everything I said above applies.
Oh and of course if it's for a Mac, in general, you could just use two USB C plugs, I suspect that's what the 4k @ 60 + 4k @ 30 is: one plug is used in DP alt mode, the other is used in MFDP mode.
- Terretta 7y agoIt doesn’t support macs with a single port because it takes two ports, uses each one. That changes the bandwidth calculator math. This adapter was, I believe, also announced at CES 2020.
- chx 7y agoOh I see now https://images-na.ssl-images-amazon.com/images/I/71z-IlmfZeL._AC_SL1500_.jpg https://images-na.ssl-images-amazon.com/images/I/71z-IlmfZeL... the single plug misled me to think it's just one USB C. Crafty.
- akiselev 7y agoIntel may have ostensibly handed the standard over to USB IF but all of the reference designs you'd use to implement a Thunderbolt dock are behind NDAs and unavailable [1] unless you get lucky, have an existing relationship, or have the volume to get their attention. [1] https://thunderbolttechnology.net/developer-application https://thunderbolttechnology.net/developer-application
- chx 7y agoYeah but it used to be that Intel needed to certify every TB3 device and they wouldn't certify a PCIe enclosure as eGPU if it chained. Neither they would an empty M.2 key M enclosure. Both now exist.
- bloopernova 7y ago> or DisplayLink which is to be avoided at all costs May I ask why, or is it the details you have later in your post?
- xmodem 7y agoDisplayLink transports video over the USB bus, rather than using one of the alt modes of USB-C. As you can imagine, this introduces compression artefacts and substantial CPU overhead. It's passable for web browsing. Watching any sort of video is painful and forget about any sort of gaming or latency sensitive application
- bloopernova 7y agoAh, this is why the displayport to 1080 screen connection looked so bad. I have a mediagear usb-c hub and also a cable matters thunderbolt to dual displayport adapter. Video is much better over the latter, for sure.
- chx 7y agoDisplayPort is fine. DisplayLink is not. The confusion is deliberate, the company renamed itself to DisplayLink a few months after the standard came out.
- chx 7y agoSources: it was USB NIVO before the DisplayPort standard came out https://www.cambridgenetwork.co.uk/news/491654 https://www.cambridgenetwork.co.uk/news/491654 and then https://www.businesswire.com/news/home/20061106005769/en/Newnham-TechnologyResearch-DisplayLink https://www.businesswire.com/news/home/20061106005769/en/New... https://glenwing.github.io/docs/DP-1.0.pdf https://glenwing.github.io/docs/DP-1.0.pdf DisplayPort Standard Version 1 May 1, 2006
- bloopernova 7y agoThank you for replying to me multiple times with concise, clear, and informative comments. I really appreciate that.