120hz support Run 4K 120Hz on LG OLED C9 using a 2014 Macbook Pro?

[Pevc]

Yeah I know, this sounds like a bit of an impossible challenge. But would it be possible to run 4K 120Hz on my new LG OLED C9 TV (55 inch model) while using my Mid 2014 Macbook Pro? (I have the one with a GeForce GT 750M 2GB inside). This will probably have to be done with some sort of adapter. But I guess those aren't available yet for HDMI 2.1 (which this TV supports). I do know that there is a StarTech Mini DisplayPort to HDMI 2.0 adapter which should enable me to run 4K 60Hz on it. Currently I'm stuck on 4K 30Hz anyways.. Which brings me to my next question.

 

Is it possible to run 120Hz in general on Mac OS on this TV with my Macbook? Currently I can't get the option to appear. Right holding Alt/Options as well, but the only option I have is 30Hz, which is not acceptable. Via bootcamp I can run windows in 1080p 120Hz. If that's possible on Mac OS too, it would be awesome. But I guess this will have to be done with some sort of command line trick? 

 

The sole reason I want 120Hz is for the smooth experience. And maybe enjoy some old (very little demanding) games on a higher frame rate. 

 

You can find the specs of the Macbook I have right here:

https://support.apple.com/kb/SP704?locale=en_US 

 

I'm currently using the HDMI out on my Macbook to connect to the TV.

 

(Side question: Is there currently even a GPU available that supports HDMI 2.1?)

[SupaKomputa]

If the output don't support HDMI 2.1 you're out of luck. The best it can support might be 60hz or even 30hz. No adapter can change that.

Side question : you should ask which GPU support 2.1.

[Firewrath9]

is that a 120hz TV?

GT 750M only supports 4k 30hz with one cable, you'd need 2 hdmi cables for 60.

[Pevc]

12 minutes ago, SupaKomputa said:

If the output don't support HDMI 2.1 you're out of luck. The best it can support might be 60hz or even 30hz. No adapter can change that.

Side question : you should ask which GPU support 2.1.

I think I am too..  Oh and good point. Updated the original post. 

 

 

[SupaKomputa]

1 minute ago, Pevc said:

I think I am too..  Oh and good point. Updated the original post. 

You should also notice that in some screen they simulate 120hz from 30hz (4x) or 60hz (2x) input, or faux refresh rate. That may explain why it's available in windows.

[Pevc]

10 minutes ago, Firewrath9 said:

is that a 120hz TV?

GT 750M only supports 4k 30hz with one cable, you'd need 2 hdmi cables for 60.

Yup, it's a TV with a 120Hz panel and it has an actual way to receive a (4K) 120Hz signal on it. But HDMI 2.1 is at the moment not widely adopted yet.

 

Maybe it technically does not support it, but in practice it does. I have a 4K monitor connected to it via a Mini DP to DP cable and that works fine for 4K 60Hz.  

[Pevc]

Oops, didn't quote 

Edited October 20, 2019 by Pevc

[Pevc]

1 hour ago, SupaKomputa said:

You should also notice that in some screen they simulate 120hz from 30hz (4x) or 60hz (2x) input, or faux refresh rate. That may explain why it's available in windows.

I did not know that. How can I check if that is happening?

[Kilrah]

1 hour ago, SupaKomputa said:

If the output don't support HDMI 2.1 you're out of luck. The best it can support might be 60hz or even 30hz. No adapter can change that.

Side question : you should ask which GPU support 2.1.

He would be "adapting" from the miniDP, not from HDMI.

 

But still, there are no DP to HDMI 2.1 adapters that exist at this point either. There's talk that club3d might be coming up with one soonish™ but then... 4K120 needs DP1.3 that a 2014 MBP certainly doesn't have since the spec was published in September 2014.

 

Also, macOS is absolutely terrible at anything but the standard resolutions/rates. There is a paid program that allows you to define one, ahd bought it back in the day (also had a 2014 MBP) but still never managed to do what I needed.

 

 

[Pevc]

10 minutes ago, Kilrah said:

He would be "adapting" from the miniDP, not from HDMI.

 

But still, there are no DP to HDMI 2.1 adapters that exist at this point either. There's talk that club3d might be coming up with one soonish™ but then... 4K120 needs DP1.3 that a 2014 MBP certainly doesn't have since the spec was published in September 2014.

 

Also, macOS is absolutely terrible at anything but the standard resolutions/rates. There is a paid program that allows you to define one, ahd bought it back in the day (also had a 2014 MBP) but still never managed to do what I needed.

 

 

Yeah maybe if the two Thunderbolt 2 / Mini DP ports could be used together with some sort of adapter, there would be a 40Gbps lane. But that's still 8Gbps shy of HDMI 2.1's 48Gbps. Maybe with some heavy compression it might work, but I hope not to give up on quality. I guess I will need to upgrade. 

 

Do you maybe still know the name of the program?

[Kilrah]

Did not, but found it: SwitchResX

[ZaziNabu]

The 120 Hrz claim is a false one, there is no way of getting it as there are no hdmi 2.1 devices and the hdmi to DP dos not support 120 Hrz in 4K.
I have that screen for 2 months and it got replaces 3 times in a months time (and i'm still waiting for it to be replaced the forth time) as it dos not support any of the claims, not the low latency on 4K HDR when connected to a PC, not the 120 Hrz, and there are lots of color bleeding and tearing at high speed videos\games.

It looks amazing at slow videos but not much else sadly. So no, you can't get it to 120 Hrz HDR at 4K nor at any other resolution.