[SOLVED] What diplay cable/ bandwidth is needed for 2560x1440 @240Hz?

[Srednal]

I have an Asus ROG 2080 Ti Rtx, and a Samsung Odyssey G7 32" monitor (supports 2560x1440 @240hz). When I connect HDMI with an 18Gbps cable, it won't do 240 Hz (stuck at 144Hz). The monitor came with a displayport cable, and initially I hooked that up- it worked at 240 Hz. After restarting the computer the displayport cable stopped working for some yet unknown reason (I just see a black screen / no viewable input despite that it looks like it's getting a signal), so I swapped back in HDMI. I've tried swapping back in the displayport cable several times but can't seem to figure out the issue. I currently am not aware of a reason the HDMI connection can't support 2560x1440 @240hz other than that I suspect the new 48Gbps cables may be needed for this (my current HDMI cables are the 18Gbps type). Anyone know about specifics of this?

 

[Lutfij]

Welcome to the forums, newcomer!

You might want to see if using DDU to uninstall the drivers for your GPU and manually reinstalling the drivers(after sourcing them from Nvidia's support site), in an elevated command, i.e, Right click installer>Run as Administrator helps you out.

I'm guessing it must be a a driver error.

 

[Glenwing]

I currently am not aware of a reason the HDMI connection can't support 2560x1440 @240hz

2560×1440 @ 240 Hz requires about 32 Gbit/s transmission speed. The maximum supported by the monitor is 18 Gbit/s, and the maximum supported by your graphics cards is 18 Gbit/s. The limitations don't come from the cable, so getting a new HDMI cable won't help. You need to use DisplayPort; refer to page 43 of the user manual.

Try disconnecting the monitor from power for a minute to reset it, see if that fixes the issue with the DisplayPort signal.

 

[Srednal]

@Glenwing I was able to fix the displayport issue by messing around with windows display settings, apparently it was actually setting the same monitor as 2 different displays and displayport was the extended display, which is still weird because it was showing a black screen vs an extended windows desktop. Thanks for the reference to the user manual. I guess it's online only since it didn't come with a physical copy.
2560 x 1440 @ 144 Hz (HDMI)
2560 x 1440 @ 240 Hz (DisplayPort)

I haven't kept up with the bandwidth supported by various revisions of different display connections so the hdmi vs displayport difference seems strange to me but the user manual page you referenced does confirm it simply won't work on hdmi at 240 Hz.

 

[DSzymborski]

@Glenwing I was able to fix the displayport issue by messing around with windows display settings, apparently it was actually setting the same monitor as 2 different displays and displayport was the extended display, which is still weird because it was showing a black screen vs an extended windows desktop. Thanks for the reference to the user manual. I guess it's online only since it didn't come with a physical copy.
2560 x 1440 @ 144 Hz (HDMI)
2560 x 1440 @ 240 Hz (DisplayPort)

I haven't kept up with the bandwidth supported by various revisions of different display connections so the hdmi vs displayport difference seems strange to me but the user manual page you referenced does confirm it simply won't work on hdmi at 240 Hz.

Yeah, the HDMI versions have typically been well behind the state-of-the-art resolution/refresh combinations for a long time. DisplayPort nowadays is the lingua franca for higher-end performance.