Appropriate monitor for Dell G3 3590 via HDMI 2.0

@Antonton  If you have V-Sync on, then frame tearing won't be an issue no matter what.  Frame tearing is what you can experience with V-Sync OFF.  Motion judder is what you can experience with V-Sync On if your GPU can't keep up with the display's refresh rate, but it sounds like you're covered there.

Wish I could help you more about the wiring question.  Unfortunately I doubt that Dell Support would even know what you were talking about here if you asked them, and if somebody gave you an answer there's a very good chance they would've just made it up or misinterpreted something.  Dell Support reps aren't always the most reliable when it comes to very technical questions like this.  That said, I do know that some G Series laptops have their HDMI outputs wired to the NVIDIA GPU specifically in order to support HDMI-based VR headsets, and the G3 3590's product page includes some system configurations marketed as "VR Ready".  If all outputs in the system were controlled by the Intel GPU, it wouldn't be possible to run VR at all (except Oculus Link to an Oculus Quest, but that's a special case).  So I would say it's likely that the HDMI output is wired to the NVIDIA GPU.  If not, then the USB-C port would be, in which case you could use a USB-C to DisplayPort cable and potentially even run G-Sync -- but again, I don't know of any Dell systems that wire their USB-C/TB3 ports to the NVIDIA GPU except those Precision systems that allow this to be configured.  What makes it especially confusing is that I've seen reports of some systems that only give you a USB-C port that supports video output if you order a configuration that includes an NVIDIA GPU -- but even in that case, the USB-C port is still wired to the Intel GPU.  Hugely confusing and annoying, and it makes me wonder why a video-capable USB-C port isn't just standard on those systems, but there you go.

@Antonton  I can help with at least some of this.

First, you can't just assume that HDMI 2.0 supports "144 Hz", because it depends on the resolution you want to run at that refresh rate.  HDMI 2.0 has enough bandwidth to support a 1080p 144 Hz display, but a 4K 144 Hz display would be way beyond its capabilities.  I'm not sure about a 1440p 144 Hz display -- but if the display documentation indicates that it can be run at its native resolution and refresh rate on its HDMI 2.0 input, then as long the system does in fact have an HDMI 2.0 output, you should be good to go.  Note that I said "should" there, partly because I don't know the details of that particular system or the display you'd be using it with, and also for some other reasons that are coming up.

I don't know what GPU has direct control of the HDMI output in that system, but when you get it, you can go to NVIDIA Control Panel and check the PhysX Configuration page.  That section includes a diagram showing which GPU has direct control of each active display -- so connect a display to the HDMI output and see which GPU is running it.  If it's the Intel GPU and the NVIDIA GPU is running through Optimus, then you can still get all the performance acceleration benefit of the NVIDIA GPU.  There are just certain more specialized technologies that don't work when the Intel GPU is in the video path, including VR, G-Sync, Adaptive V-Sync, stereoscopic 3D, and maybe some others.

G-Sync only works over DisplayPort, so it won't work over HDMI regardless of which GPU runs the HDMI output.  G-Sync can also work from a USB-C port since USB-C uses DisplayPort for video -- as long as you don't use something like a USB-C to HDMI cable/adapter, in which case you're back to HDMI.  But again, you need a DisplayPort output that is directly controlled by the NVIDIA GPU, which this system likely won't have.  The only systems I know of that have that are modern Alienware systems that have a Mini-DisplayPort output wired directly to the NVIDIA GPU, and then Precision 7000 Series systems that have a BIOS option allowing the user to choose whether the Intel or NVIDIA GPU has direct control of the display outputs.  Other than that, as far as I know, all current Dell laptops that have USB-C/TB3 ports have those ports wired to the Intel GPU, even if their HDMI output is wired to the NVIDIA GPU.  Wiring the HDMI output to the NVIDIA GPU was done on some laptops to allow VR to be used through those ports, although even that's become a challenge because some VR headsets now require a DisplayPort source rather than HDMI.

The part I'm not sure about is whether Intel GPUs support 144 Hz at all, regardless of resolution or capabilities of the display output port.  I've seen confirmation that they can run 120 Hz, but not sure about 144 Hz.  However, note that even if the Intel GPU DOES support high refresh rates, again it will NOT allow you to use G-Sync, and it won't allow Adaptive V-Sync either.  That creates a problem for high refresh rates, because it means your only options are V-Sync Off or V-Sync On.  Running V-Sync Off means you can experience frame tearing, which is what V-Sync is designed to prevent.  But running V-Sync On is difficult if you’re running a high refresh rate because you then need to make sure that your GPU can sustain a frame rate at least as high as your display's refresh rate, because if the frame rate drops and the GPU doesn't have a rendered frame ready for when the display refreshes, then the GPU will repeat its previous video frame to "buy more time", which you'll notice as motion judder.  And getting a stable 144 fps might be tricky.  This is the exact dilemma that G-Sync is meant to solve by allowing the best of both worlds, where you have no tearing AND no judder because the display’s refresh rate adjusts dynamically based on what the GPU can deliver, but that’s not possible through Optimus (or through an HDMI output).

Thanks - all really helpful.  I’ve had a quick look and the expectation is that the laptop should easily give me over 144fps on CSGO based on https://www.dell.com/en-uk/shop/gaming-and-games/dell-g3-15/spd/g-series-15-3590-laptop/cn35906?view=configuration. It’s quite a low maintenance game (having been out for over 8 years). Therefore the frame tear you mention below shouldn’t hopefully be an issue if I have v-sync on? 

My only concern is whether the HDMI output is the Intel GPU or Nvidia GPU and if the Intel GPU supports 144hz. It’s difficult without having the laptop (so I wonder if it’s something someone who has the laptop or the Dell team can support me with). Otherwise, I’m minded to refund to a different model.

Thanks again for your help.

The model that I bought definitely said it was VR ready, (for use with Oculus Rift or HTC VIVE), so that suggests to me one of the outputs (HDMI or USB-C) is connected to the Nvidia GPU. Based on everything I’ve read, it sounds like it’s almost definitely connected to HDMI - is that a fair assumption?  This is the laptop again - 

https://www.dell.com/en-uk/shop/gaming-and-games/dell-g3-15/spd/g-series-15-3590-laptop/cn35906?view=configurations. 

On the screen tearing point, I think CS:GO vsync has significant mouse input lag - would another solution to eliminate this be to cap the frame rate to 144 FPS? Theoretically that should solve the issue without vsync on?

@Antonton  if the spec calls out the Oculus Rift and HTC VIVE, then the HDMI port is definitely wired to the NVIDIA GPU because both of those headsets use HDMI.  However, the newer Rift S uses DisplayPort, just fyi.

As for capping the frame rate to 144 fps, that's essentially what enabling V-Sync would do, so if CS:GO has problems with V-Sync, I'd be surprised if capping it to 144 fps behaved differently.  But if that somehow works, I would expect that to solve frame tearing, assuming that it aligned the capped frame rendering rate to the display refresh rate in the first place, otherwise you'd get consistent tearing because things would be permanently out of sync.  But I'm not a heavy gamer so I can't say for sure.

I has this notebook model and bought an 144Hz monitor. I want to use 2 monitors, so bought too a usb c - display port cable but display port is connected to intel graphics gpu. Both (hdmi and dp) let me get 144hz but when i play i want the dedicated graphic performance. This disappointed mt 'cause i was trying to use g sync

@Antonton