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I got 2 LG 4k monitors plugged into my Mac Mini M1, one USB-C (43 inch), and one HDMI (27 inch rotated). In both cases the Mac runs them at 60 hz, the 43 inch s

I got 2 LG 4k monitors plugged into my Mac Mini M1, one USB-C (43 inch), and one HDMI (27 inch rotated). In both cases the Mac runs them at 60 hz, the 43 inch slightly scaled and the 27 inch around 1440p scaling. If I put them at full resolution (unscaled) they still run at 60hz.

edgan 5y ago
I think you mean Thunderbolt not USB-C. Thunderbolt ties into the GPU, but USB-C doesn't.
- kelchm 5y ago
  USB-C is simply the connector format -- which can then be used as either USB 4 or Thunderbolt 3. The highest speed USB 4 devices are effectively the same as Thunderbolt 3 from what I understand. I really do sympathize with any consumer who has to try to make sense of what a given port is actually capable of these days.
  - B1FF_PSUVM 5y ago
    The Chuwi Hi10x is a nice enough Windows tablet - sort of a cheap and cheerful Surface, but really a grandkid of the Asus T100. It is powered with a 12V, 2A charger via one USB C port (and just one of the existing two). But try to use a standard USB-C PD charger, and nothing happens. However it does charge with a plain 12V charger, sporting a USB C jack, that does not require PD negotiation ... I'm coming to think that having one connector for everything may not be easy ...
- bhouston 5y ago
  I am confused generally. My old Dell xps 13 didn’t have thunderbolt but I could still use the exact same USB c to display port cable that I used on my Mac mini. I am unsure if you need thunderbolt specifically to use USB c to display port cables. It seems you do not need thunderbolt but I am not an expert.
  - ryukafalz 5y ago
    > I am unsure if you need thunderbolt specifically to use USB c to display port cables. It seems you do not need thunderbolt but I am not an expert. Correct, you do not need Thunderbolt for this. Most laptops with USB-C support something called DisplayPort Alt Mode, which is essentially DisplayPort over the type-C connector; I'd imagine that's what those cables are doing. Now, if you have a Thunderbolt display specifically, like the ones Apple used to sell? Your type-C port would need to support Thunderbolt to use that.
    - vetinari 5y ago
      If you are using USB-C in alternate mode, it means that you forego everything else: with USB-C cable, you can basically use USB2, power delivery and (USB3 or alternate mode) at the same time. Funny things happen when the alternate mode is Thunderbolt. It allows to tunnel DisplayPort and USB3 traffic, so when you are using TB alt mode, you still have usable DP and USB3, not USB-C natively, but packetized inside TB3 traffic. For 2x20 GBit TB3 traffic, you need much better cable than what the average USB3/USB-C cable can handle (that's the reason why they are sold as TB cables); if it is anything above 0.5m, it is usually active one. And to make things even more interesting, there are USB-C cables than cannot handle even USB3/alt modes... so it is important to check the specs, not only price tag.
      - danieldk 5y ago
        If you are using USB-C in alternate mode, it means that you forego everything else: with USB-C cable, you can basically use USB2, power delivery and (USB3 or alternate mode) at the same time. Incorrect. Perhaps with a low-end adapter, but with a higher end dock (and sufficiently modern hardware that supports DP1.3) you can drive 4k@60Hz [1], USB 3.2 Gen 2 10Gbit/s, USB 2, and PD at the same time over a single USB-C cable. For example, the Lenovo USB-C Dock Gen 2 that I use does this without any issues. The configuration is that two superspeed lanes are used for USB 3.2. The other two superspeed lanes are used for DP-Alt, which have 8.1Gbit/s bandwidth per lane with HBR3 for a total of 16.2, which is perfectly fine for 4k@60Hz. You can even do higher resolutions with DSC (though I am not sure which, if any, docks support this). [1] Or lower resolutions/refresh rates with HBR2.
aulin 5y ago
how deep is your desk to be able to use all that screen real estate? I already suffer eye strain with my 34 4k as it's already too high
- FpUser 5y ago
  Not Mac user but here is my experience with multi-monitor. I used to have 2 32" 4K monitors at full resolution. One was pivoted to vertical specifically for coding. My main desk resembles an airfield so space wise it was ok. However recently I found myself tired to turn my head and body when shifting attention between two. I am back to just a single 32" 4K. The other monitor went to a different computer.
- jsjohnst 5y ago
  I’m using standard office sized standing desks (40”x60”). On my “work” desk I have two 27” LG5K displays side by side with the laptop off to the side. My second “personal” desk has two 27” Apple Thunderbolt monitors stacked vertically with two 34” LG ultrawides turned vertically on either side of the stacked 27”. No eye strain or neck issues with either setup.
  - aulin 5y ago
    Horizontally I can add as much displays as I want but as soon as my main ones are higher than a typical 32" height my eyes begin to suffer. Could be because top and bottom areas start to lie on too different focal planes. Horizontally you can arrange them on an arc to be all at the same distance and the problem is mitigated

edgan 5y ago

I think you mean Thunderbolt not USB-C. Thunderbolt ties into the GPU, but USB-C doesn't.

kelchm 5y ago
USB-C is simply the connector format -- which can then be used as either USB 4 or Thunderbolt 3. The highest speed USB 4 devices are effectively the same as Thunderbolt 3 from what I understand. I really do sympathize with any consumer who has to try to make sense of what a given port is actually capable of these days.
- B1FF_PSUVM 5y ago
  The Chuwi Hi10x is a nice enough Windows tablet - sort of a cheap and cheerful Surface, but really a grandkid of the Asus T100. It is powered with a 12V, 2A charger via one USB C port (and just one of the existing two). But try to use a standard USB-C PD charger, and nothing happens. However it does charge with a plain 12V charger, sporting a USB C jack, that does not require PD negotiation ... I'm coming to think that having one connector for everything may not be easy ...
bhouston 5y ago
I am confused generally. My old Dell xps 13 didn’t have thunderbolt but I could still use the exact same USB c to display port cable that I used on my Mac mini. I am unsure if you need thunderbolt specifically to use USB c to display port cables. It seems you do not need thunderbolt but I am not an expert.
- ryukafalz 5y ago
  > I am unsure if you need thunderbolt specifically to use USB c to display port cables. It seems you do not need thunderbolt but I am not an expert. Correct, you do not need Thunderbolt for this. Most laptops with USB-C support something called DisplayPort Alt Mode, which is essentially DisplayPort over the type-C connector; I'd imagine that's what those cables are doing. Now, if you have a Thunderbolt display specifically, like the ones Apple used to sell? Your type-C port would need to support Thunderbolt to use that.
  - vetinari 5y ago
    If you are using USB-C in alternate mode, it means that you forego everything else: with USB-C cable, you can basically use USB2, power delivery and (USB3 or alternate mode) at the same time. Funny things happen when the alternate mode is Thunderbolt. It allows to tunnel DisplayPort and USB3 traffic, so when you are using TB alt mode, you still have usable DP and USB3, not USB-C natively, but packetized inside TB3 traffic. For 2x20 GBit TB3 traffic, you need much better cable than what the average USB3/USB-C cable can handle (that's the reason why they are sold as TB cables); if it is anything above 0.5m, it is usually active one. And to make things even more interesting, there are USB-C cables than cannot handle even USB3/alt modes... so it is important to check the specs, not only price tag.
    - danieldk 5y ago
      If you are using USB-C in alternate mode, it means that you forego everything else: with USB-C cable, you can basically use USB2, power delivery and (USB3 or alternate mode) at the same time. Incorrect. Perhaps with a low-end adapter, but with a higher end dock (and sufficiently modern hardware that supports DP1.3) you can drive 4k@60Hz [1], USB 3.2 Gen 2 10Gbit/s, USB 2, and PD at the same time over a single USB-C cable. For example, the Lenovo USB-C Dock Gen 2 that I use does this without any issues. The configuration is that two superspeed lanes are used for USB 3.2. The other two superspeed lanes are used for DP-Alt, which have 8.1Gbit/s bandwidth per lane with HBR3 for a total of 16.2, which is perfectly fine for 4k@60Hz. You can even do higher resolutions with DSC (though I am not sure which, if any, docks support this). [1] Or lower resolutions/refresh rates with HBR2.

aulin 5y ago

how deep is your desk to be able to use all that screen real estate? I already suffer eye strain with my 34 4k as it's already too high

FpUser 5y ago
Not Mac user but here is my experience with multi-monitor. I used to have 2 32" 4K monitors at full resolution. One was pivoted to vertical specifically for coding. My main desk resembles an airfield so space wise it was ok. However recently I found myself tired to turn my head and body when shifting attention between two. I am back to just a single 32" 4K. The other monitor went to a different computer.
jsjohnst 5y ago
I’m using standard office sized standing desks (40”x60”). On my “work” desk I have two 27” LG5K displays side by side with the laptop off to the side. My second “personal” desk has two 27” Apple Thunderbolt monitors stacked vertically with two 34” LG ultrawides turned vertically on either side of the stacked 27”. No eye strain or neck issues with either setup.
- aulin 5y ago
  Horizontally I can add as much displays as I want but as soon as my main ones are higher than a typical 32" height my eyes begin to suffer. Could be because top and bottom areas start to lie on too different focal planes. Horizontally you can arrange them on an arc to be all at the same distance and the problem is mitigated