HDMI 1.4b max refresh rate (2560 x 1080)

[Nullosta]

I have a Lenovno Y510P, and I've recently bought LG 34UC79G-B (2560 x 1080) which supports 144Hz.

 

After connecting my laptop to the monitor via HDMI (My laptop has no display port) it seems that there's no 

support for 144Hz, but google says otherwise and that it should support 144Hz.

I've tried going through the advanced display settings and the max refresh rate was 75Hz.

 

Can anyone please confirm if I'm doing something wrong? 

 

[mathijs727]

I think HDMI 1.4 can only do 144Hz at 1920x1080 not 2560x1080.

Following the logic in the top rated post of this Reddit topic the theoretical maximum frame rate is 98Hz (272e6 / (2560 * 1080)).

[Eigenvektor]

You can use this bandwidth calculator to calculate the required bandwidth: https://k.kramerav.com/support/bwcalculator.asp (don't forget to click the "submit" button if you enter custom values...)

 

It says for 2560x1080 @ 144 Hz you need 11.94 Gbps. HDMI 1.4b has a maximum bandwidth of 8.16 Gbps, so 98 Hz sounds about right (comes out to 8.13 Gbps).

[Constantin]

31 minutes ago, mathijs727 said:

I think HDMI 1.4 can only do 144Hz at 1920x1080 not 2560x1080.

Following the logic in the top rated post of this Reddit topic the theoretical maximum frame rate is 98Hz (272e6 / (2560 * 1080)).

You are wrong!

[mathijs727]

3 minutes ago, Constantin said:

You are wrong!

According to the HDMI spec website, HDMI 1.4b is limited to 120hz at 1920x1080(so anything above is out of spec):

https://www.hdmi.org/spec/hdmi1_4b

[Constantin]

2 minutes ago, mathijs727 said:

According to the HDMI spec website, HDMI 1.4b is limited to 120hz at 1920x1080(so anything above is out of spec):

https://www.hdmi.org/spec/hdmi1_4b

So you are saying the chart is wrong? from Wiki?

[mathijs727]

1 minute ago, Constantin said:

So you are saying the chart is wrong? from Wiki?

What I'm saying is that it has the bandwidth and devices might support it, BUT it is not officially part of the specification.

[TVwazhere]

17 minutes ago, Constantin said:

So you are saying the chart is wrong? from Wiki?

Wikipedia isnt a be-all, end-all source of information. Wiki can be a good source of sources, but since anyone with a computer can edit a page, it cannot be taken at face value (even if the editor has the best intentions in mind) since their source could be bad, wrong or outdated.

 

Also, just looking at the pictures doesnt tell you the whole story. @mathijs727's point is actually in the Wikipedia article right above the graph.

Quote

 Formats that are not supported by the HDMI Specification (i.e., no standardized timings defined) may be implemented as a vendor-specific format