@sj86 Thunderbolt capabilities only come into play when dealing with actual Thunderbolt hardware, and your LG display appears to be a USB-C display, not a Thunderbolt display. Thunderbolt displays are relatively rare. But even if you DID have Thunderbolt, that would give you two full DP 1.2 interfaces plus PCIe. That would be enough bandwidth to run dual 4K 60 Hz and USB 3.x simultaneously, but even though that's all running over a single cable, from the GPU's standpoint those are two separate interfaces, and I don't think you can combine their bandwidth to drive a single display. NVIDIA and AMD GPUs support that sort of interface aggregation, and in fact Dell's early 5K display and their 8K display leveraged that capability to run their native resolution and refresh rate over two physical cable connections since a single connection of their eras didn't offer enough bandwidth. But you'd still have the problem that DisplayPort 1.2 as a spec has no formal support for any of the HDR standards anyway.
If you want to learn more about this, I actually wrote an explainer post about the various modes of USB-C and Thunderbolt ports, including their impact on display capabilities, over here. It causes so much confusion that I figured it was worth organizing that information somewhere, so there you go.
@sj86 If you want to use 4K 60 Hz from a non-Thunderbolt display, yes you'd want to run USB data over a separate cable. If the display itself provided an extra port for that purpose, then you would just have two cables between your PC and the display. Otherwise you could get a separate USB 3 hub. But to be clear, there's no sort of "splitter cable" you could use on the display side in order to have two cables from your system converge into a single USB-C port on the display and achieve full functionality. You can perform that sort of breakout on the system side, i.e. a dongle that plugs into a system USB-C port and gives you separate video and USB ports, but you can't aggregate signals on the peripheral side.
The alternative would be to get 4K 60 Hz display that actually supports Thunderbolt. Those do exist, and in fact LG makes some. Those will allow 4K 60 Hz and USB 3.x simultaneously, in fact you could even daisy chain a second 4K 60 Hz Thunderbolt display in that setup and still only have a single cable coming from your system running everything, but they are likely to be more expensive.
@sj86 wrote:
Hi,
I recently bought an LG 32un880-b monitor.
When I connect my dell laptop to it with the provided usb-c cable the laptop charges but it cannot find the monitor.
I tried all the ports of my laptop and the cable is usb-c to usb-c without any hubs in between and also while charging the laptop with the power adapter.
Good to see that @jphughan is here helping you (as he is an expert on these kinds of issues) . I just wanted to drop in and mention that the Monitor should never been charging the laptop.
Do whatever you want with other cables, but be sure to connect the supplied Dell (USB-C plugged and proper-wattage) AC-Adapter directly to the laptop. There are very few exceptions to this rule.
And finally, not sure if this is any help, but I did recently test an external monitor on a XPS here:
@Tesla1856 The specs of that display indicate that it provides up to 60W of power, and the XPS 13 is designed to require only 45W for optimum functionality. It’s actually pretty common for USB-C displays to provide at least some amount of power, typically at least 60W and sometimes as much as 95W, and many laptops will run optimally or at least acceptably within those power levels, so I’m not sure why you’d say that there are very few exceptions to the rule that you need the system AC adapter directly connected.
@jphughan wrote:
@Tesla1856 The specs of that display indicate that it provides up to 60W of power, and the XPS 13 is designed to require only 45W for optimum functionality. It’s actually pretty common for USB-C displays to provide at least some amount of power, typically at least 60W and sometimes as much as 95W, and many laptops will run optimally or at least acceptably within those power levels, so I’m not sure why you’d say that there are very few exceptions to the rule that you need the system AC adapter directly connected.
See, that is why you are the expert.
It's just that they were having issues, so I thought it might be better if they supplied the laptop with plenty of power, and deal with monitor issues on only a signal/communication level. You can always change it later (after issue is resolved).
Not sure about you, but I consider using an external monitor with a laptop rare.
Docking-Stations and Hubs also fairly rare. However, I've seen recent monitors advertised as having "Built-in Internal Hub" so maybe that is where things are going now. People just can't seem to resist the urge to build multiple machines together into one. Yes, I can see the use-case as many using a docking-station/hub also use a real (larger) monitor. Personally, I would rather have the flexibility to more-easily re-configure systems or even move monitors around (to different desks) as the years go by.
@Tesla1856 Maybe using a laptop with an external display is somewhat rare. That might explain how Apple has now gone two generations of its CPUs where the base model only supports two total displays, which means only one external display on laptops, even if the internal display isn’t being used — despite the fact that the Intel CPUs they replaced two years ago could handle three total displays.
But we’re obviously dealing with someone who does use an external display here, and among that market, the availability of displays that essentially have built-in docking stations has been increasing. That’s probably in response to the fact that laptops are increasingly replacing desktops, and those are increasingly moving to fewer total ports and having USB-C/TB as the sole TYPE of port. That means being able to connect peripherals to the display rather than directly to the system is handy, and it also just means it’s POSSIBLE to have a universal docking station in a display. For businesses, that means one less component to buy as long as the capabilities of the built-in dock are sufficient. Thunderbolt docks still offer more capability, primarily around display setups that can be driven.
But yes, flexibility and possibly the ability to upgrade one component without the other have their place too. That’s undoubtedly part of why many of Dell’s displays for the last few years have had two model variants, one with one without the built-in dock. Businesses that are using displays with Thunderbolt docks or simply with desktop systems therefore have a way to avoid spending money on functionality they don’t need or want to have in their displays. But those who would otherwise have purchased USB-C docks have an option for a simpler and less expensive setup. The last couple generations of Dell USB-C displays have even incorporated Ethernet, not to put the display on the network but to provide a wired Ethernet connection to the docked system.
It’s good to have choices!
@sj86 Thanks for reporting back! I never would have expected that outcome given that you successfully tested the display and cable with another system. Now I’m wondering what the difference is between those two displays, but I guess we’ll never know. But glad to hear you’re good to go!
