External display lag while using usb-c

[iMDarker]

Monitor :Samsung C24FG73(hdmi ,dp)

Laptop: Dell 7577 (thunderbolt3, hdmi)

I've recently bought the monitor listed and to get the 144hz i've been using usb-c from my dell 7577 to dp in monitor. When i use usb-c my pc usually slows down and i get -50 fps on games like lol and fortnite; i've tried using hdmi(only 120hz max) and i've been getting no lag while playing games.

What could be the problem that makes me lag while using usb-c

[Quadrum]

If hdmi works then you’ll have to do that. But i believe that the usb-c in this case is being bottlenecked by the mobo. In laptops the I/o is limited to a small amount of bandwidth for battery and it could be the cause of the lag. Good luck!

[Glenwing]

3 hours ago, Quadrum said:

If hdmi works then you’ll have to do that. But i believe that the usb-c in this case is being bottlenecked by the mobo. In laptops the I/o is limited to a small amount of bandwidth for battery and it could be the cause of the lag. Good luck!

The USB-C port is just a passthrough for DisplayPort, the display traffic isn't subject to the bandwidth limits of the USB version. Even if it were, it wouldn't affect fps in games, only the refresh rate of the display.

3 hours ago, iMDarker said:

Monitor :Samsung C24FG73(hdmi ,dp)

Laptop: Dell 7577 (thunderbolt3, hdmi)

I've recently bought the monitor listed and to get the 144hz i've been using usb-c from my dell 7577 to dp in monitor. When i use usb-c my pc usually slows down and i get -50 fps on games like lol and fortnite; i've tried using hdmi(only 120hz max) and i've been getting no lag while playing games.

What could be the problem that makes me lag while using usb-c

Most likely the laptop is set up so that the USB-C/DisplayPort port is connected to the CPU's integrated graphics, while the HDMI port is provided by the dedicated GPU.

[iMDarker]

On 18/5/2018 at 11:15 PM, Glenwing said:

The USB-C port is just a passthrough for DisplayPort, the display traffic isn't subject to the bandwidth limits of the USB version. Even if it were, it wouldn't affect fps in games, only the refresh rate of the display.

Most likely the laptop is set up so that the USB-C/DisplayPort port is connected to the CPU's integrated graphics, while the HDMI port is provided by the dedicated GPU.

Is there are a way to set the usb-c to gpu?

[Glenwing]

7 hours ago, iMDarker said:

Is there are a way to set the usb-c to gpu?

 

There may be an option in the BIOS to use only the NVIDIA GPU, but that may just disable the USB-C port's display output entirely, assuming the option is even there. No way to know without testing it really.