[SOLVED] 144hz display only showing 120hz

[Grifent]

Just bought a ViewSonic vx2758-c-mh 1080p 144hz display. The specs claim that it only supports 144hz over HDMI, and I am using the supplied HDMI cable from the box, but highest refresh rate I can achieve is 120hz. Graphics card is an r9 380 (which has HDMI 1.4), and I've tried setting 144hz manually in AMD's drivers but it just says the display doesn't support the selected resolution. I've also downloaded the drivers for the monitor from Viewsonic's website, although they don't seem to appear in device manager, it only comes up as Generic PnP Monitor. 120hz is fine but I'd like to get the most out of the monitor if I can. Do I need to get a DisplayPort to HDMI cable or am I just missing something?

 

[Mrgr74]

Is the supplied cable an HDMI to DVI-I (or DVI-D) or is it HDMI on both ends? Does your monitor have a DP port? I know your GPU does.

Your monitor has an HDMI 1.4 & HDMI 2.0 port on the back. Have you tried both ports &/or an HDMI 2.0 cable?

Some generic info:

"To output 1080p content at 144Hz, you will need either a Dual-Link DVI, a DisplayPort, or an HDMI 1.4 or higher (though some monitors with HDMI 1.4 are limited to 60Hz or 120Hz) cable.

For 144Hz at 1440p, you will need at least an HDMI 2.0 or a DisplayPort 1.2 while for 4K 144Hz you are going to need an HDMI 2.1 or alternatively, a DisplayPort 1.4 which maxes out at 120Hz without compression."

 

[Grifent]

Is the supplied cable an HDMI to DVI-I (or DVI-D) or is it HDMI on both ends?

Some generic info:

"To output 1080p content at 144Hz, you will need either a Dual-Link DVI, a DisplayPort, or an HDMI 1.4 or higher (though some monitors with HDMI 1.4 are limited to 60Hz or 120Hz) cable.

For 144Hz at 1440p, you will need at least an HDMI 2.0 or a DisplayPort 1.2 while for 4K 144Hz you are going to need an HDMI 2.1 or alternatively, a DisplayPort 1.4 which maxes out at 120Hz without compression."

It's HDMI to HDMI.

 

[Mrgr74]

It's HDMI to HDMI.

HDMI 1.4 @ 144hz should work if you are at 1080p. I wonder if your particular cable only goes to 120hz?

Here is some good general info:
https://forums.tomshardware.com/threads/how-to-connect-to-a-120-hz-display.3268285/

 

[Grifent]

HDMI 1.4 @ 144hz should work if you are at 1080p. I wonder if your particular cable only goes to 120hz?

Here is some good general info:
https://forums.tomshardware.com/threads/how-to-connect-to-a-120-hz-display.3268285/

Well the cable itself says 'High Speed HDMI Cable with Ethernet', and as far as I can tell from that thread, that should support 1080p 144hz. I've also heard people say that AMD's drivers are to blame for a lack of 144hz support over HDMI, but is there any credibility to that?

 

[Mrgr74]

'High Speed HDMI Cable with Ethernet', I've also heard people say that AMD's drivers are to blame for a lack of 144hz support over HDMI, but is there any credibility to that?

A local resident guru here will need to verify, but I just read that of the 4 HDMI specs, your High Speed HDMI Cable with Ethernet is 2.0 and so should have 0 problems. Does your monitor itself have any settings to switch between Hz? I ask because mine does when I switch from 144hz to 120hz Freesync. When you try to switch res via desktop and not your AMD software, do you still see the same max 120hz?

As for AMD, I'm going to have to defer to someone here with an AMD card to answer that as I'm not having an issue @ 144hz on my 1060.

 

[Glenwing]

Just bought a ViewSonic vx2758-c-mh 1080p 144hz display. The specs claim that it only supports 144hz over HDMI, and I am using the supplied HDMI cable from the box, but highest refresh rate I can achieve is 120hz. Graphics card is an r9 380 (which has HDMI 1.4), and I've tried setting 144hz manually in AMD's drivers but it just says the display doesn't support the selected resolution. I've also downloaded the drivers for the monitor from Viewsonic's website, although they don't seem to appear in device manager, it only comes up as Generic PnP Monitor. 120hz is fine but I'd like to get the most out of the monitor if I can. Do I need to get a DisplayPort to HDMI cable or am I just missing something?

Please try setting a custom resolution again, making sure to follow all the instructions in section 6.3 here: https://forums.tomshardware.com/threads/how-to-connect-to-a-120-hz-display.3268285/

 

[kerberos_20]

according to hdmi specs, hdmi 1.4b doesnt support 144hz on 1080p, 120hz is max
so u will need to use display port for 144hz or get new gpu with hdmi 2.0

 

[Glenwing]

according to hdmi specs, hdmi 1.4b doesnt support 144hz on 1080p, 120hz is max
so u will need to use display port for 144hz or get new gpu with hdmi 2.0

That is not correct. Please see section 5 here: https://forums.tomshardware.com/threads/how-to-connect-to-a-120-hz-display.3268285/

 

[kerberos_20]

That is not correct. Please see section 5 here: https://forums.tomshardware.com/threads/how-to-connect-to-a-120-hz-display.3268285/

with custom resolution ok
but on default 1080p (lcd native) @ 144Hz/162kHz it needs 356.4Mhz pixel clock, while hdmi 1.4 has max pixel clock 340MHz

 

[Glenwing]

with custom resolution ok
but on default 1080p (lcd native) @ 144Hz/162kHz it needs 356.4Mhz pixel clock, while hdmi 1.4 has max pixel clock 340MHz

Manufacturers can use any timings they want, they don't have to stick to standardized timing formulas.

See here: https://linustechtips.com/main/blogs/entry/1429-viewsonic-xg2401-144-hz-over-hdmi-testing/

 

[kerberos_20]

Manufacturers can use any timings they want, they don't have to stick to standardized timing formulas.

See here: https://linustechtips.com/main/blogs/entry/1429-viewsonic-xg2401-144-hz-over-hdmi-testing/

true, but i think radeon has limited pixel clock to around 300mhz
r9 390 has max resolution 4096*2160 @ 24hz...which is up to 280MHz pixel clock, 30Hz is over 300mhz - not supported

 

[Grifent]

A local resident guru here will need to verify, but I just read that of the 4 HDMI specs, your High Speed HDMI Cable with Ethernet is 2.0 and so should have 0 problems. Does your monitor itself have any settings to switch between Hz? I ask because mine does when I switch from 144hz to 120hz Freesync. When you try to switch res via desktop and not your AMD software, do you still see the same max 120hz?

As for AMD, I'm going to have to defer to someone here with an AMD card to answer that as I'm not having an issue @ 144hz on my 1060.

No setting on the monitor to change refresh rate AFAIK. Changing via Windows still only shows 120hz, I checked all available resolutions and none showed 144hz. Starting to think it's more of a GPU issue

 

[Grifent]

true, but i think radeon has limited pixel clock to around 300mhz
r9 390 has max resolution 4096*2160 @ 24hz...which is up to 280MHz pixel clock, 30Hz is over 300mhz - not supported

If that's the case then would a displayport to HDMI cable fix this? (Using displayport from the GPU)

 

[Mrgr74]

If that's the case then would a displayport to HDMI cable fix this? (Using displayport from the GPU)

I took a look at the ports on the back of your monitor and unless I looked at the wrong monitor (which is entirely possible since I've not had any coffee yet) your monitor didn't have a DP. You'd need a DP to HDMI converter. DP from your PC to the monitors HDMI port. Have you tried a different PC to make sure everything is OK on the monitors side or even a different GPU?

 

[Grifent]

I took a look at the ports on the back of your monitor and unless I looked at the wrong monitor (which is entirely possible since I've not had any coffee yet) your monitor didn't have a DP. You'd need a DP to HDMI converter. DP from your PC to the monitors HDMI port. Have you tried a different PC to make sure everything is OK on the monitors side or even a different GPU?

I could try but the only other PCs I have available to me use integrated graphics, so would those even display an option for 144hz?
And yeah, the monitor only has HDMI so I assume I'd need a DisplayPort to HDMI active converter.

 

[Glenwing]

true, but i think radeon has limited pixel clock to around 300mhz
r9 390 has max resolution 4096*2160 @ 24hz...which is up to 280MHz pixel clock, 30Hz is over 300mhz - not supported

I had an R9 290, and it supports the full 340 MHz TMDS clock over HDMI. The 120 Hz limit is due to a driver restriction, which can be bypassed (see here).

If that's the case then would a displayport to HDMI cable fix this? (Using displayport from the GPU)

Please try running the AMD pixel clock patcher and restarting, then setting a custom resolution with CVT-RB timing as instructed in section 6.3.2 here: https://forums.tomshardware.com/threads/how-to-connect-to-a-120-hz-display.3268285/

 

[Grifent]

I had an R9 290, and it worked just fine up to 340 Mpx/s. The 120 Hz limit is due to a driver restriction, which can be bypassed (see here).


Please try running the AMD pixel clock patcher and restarting, then setting a custom resolution with CVT-RB timing as instructed in section 6.3.2 here: https://forums.tomshardware.com/threads/how-to-connect-to-a-120-hz-display.3268285/

I was about to try this, I'll update with the results shortly.

 

[Grifent]

I had an R9 290, and it supports the full 340 MHz TMDS clock over HDMI. The 120 Hz limit is due to a driver restriction, which can be bypassed (see here).


Please try running the AMD pixel clock patcher and restarting, then setting a custom resolution with CVT-RB timing as instructed in section 6.3.2 here: https://forums.tomshardware.com/threads/how-to-connect-to-a-120-hz-display.3268285/

That fixed it! Thanks for all the help