HDMI 1.4 supports 120hz....what?

[79wjd]

http://www.displaylag.com/ces-2014-vizio-debuts-4k-120-inch-120-fps-local-dimming-hdtvs/

 

 

Unfortunately, Playstation 4 and Xbox One users will not be able to see the benefits of true 120hz, but it’s very exciting to see the first HDTVs starting to allow 120hz input without resorting to unofficial workarounds. Being able to display 120hz through HDMI also has an excellent side effect: the reduction of input lag! ........ The best part? You don’t need HDMI 2.0 to make this work, as Vizio is fully supporting High Velocity mode even through HDMI 1.4! Now if only this mode was present in the M-Series as well… one can dream.

I thought HDMI1.4 couldn't support 1080p @ 120hz

[91wow]

They're using 60Hz and then kinda in a way drawing an extra frame on the TV so 1 frame input=2 frame output in a way. It's how those 240Hz and higher 1080P tv's and monitors do it. 

[Captain_Slow]

the tv does 4k @ 60hz, and 1080p at 120hz

[Captain_Slow]

and It's got 1 hdmi 2.0 port, so I will accept 120fps

[79wjd]

They're using 60Hz and then kinda in a way drawing an extra frame on the TV so 1 frame input=2 frame output in a way. It's how those 240Hz and higher 1080P tv's and monitors do it.

I know thats how most 120hz+ panels work; but its listing it at 'true 120hz' though.

see the benefits of true 120hz, but it’s very exciting to see the first HDTVs starting to allow 120hz input without resorting to unofficial workarounds."

 

the tv does 4k @ 60hz, and 1080p at 120hz

and It's got 1 hdmi 2.0 port, so I will accept 120fps

But it says it works with HDMI 1.4

[Aniallation]

My Insignia TV has HDMI 1.4. It says "1080p" and "120Hz" on the box, but not in the same context. Which is why at 1080p it's maximum 60Hz, but bumping resolution down to 720p allows you to select native 120Hz in Windows

[Captain_Slow]

I know thats how most 120hz+ panels work; but its listing it at 'true 120hz' though.

 

But it says it works with HDMI 1.4

no the tv has 3 HDMI 1.4 ports and 1 HDMI 2.0 port. 120 fps and 4k content has to go through 2.0

[79wjd]

no the tv has 3 HDMI 1.4 ports and 1 HDMI 2.0 port. 120 fps and 4k content has to go through 2.0

Running a game at 120 FPS should result in 50% less input lag over a game running at 60hz, so you can imagine the difference! The best part? You don’t need HDMI 2.0 to make this work, as Vizio is fully supporting High Velocity mode even through HDMI 1.4! 

 

Thats not what they're saying though; unless they're trying to say that over HDMI 2.0 it will do true 120hz, but HDMI 1.4 will use some form of interpolation. 

[Captain_Slow]

 

Thats not what they're saying though; unless they're trying to say that over HDMI 2.0 it will do true 120hz, but HDMI 1.4 will use some form of interpolation. 

 

well running a game at 120fps will reduce input lag even on a 60 hz monitor.

 

but to see 120fps smoothness you need hdmi 2.0 on that tv.

[79wjd]

well running a game at 120fps will reduce input lag even on a 60 hz monitor.

 

but to see 120fps smoothness you need hdmi 2.0 on that tv.

Shouldn't it have a higher input lag caused by interpolation? 

[Captain_Slow]

Shouldn't it have a higher input lag caused by interpolation? 

 

no

 

most game engine works based on frames rendered

 

so your actions on your mouse and keyboard won't be registered until the next frame is rendered in game.

 

so if you are running 10 fps, you will have 100ms input lag, if you are running 100 fps, you have 10 ms input lag, and so on.

 

vizio is basically doing bullshit marketing by saying their tv supports this because it has nothing to do with the display at all.

[Phillyphries]

There's HDMI 1.4a

(Biggest change here is added 3D support at 1080p @ 24hz maximum)

 

Then there's HDMI 1.4b

(Allowing 1080p 3D @ 60 hz per eye [120hz total])

 

I think HDMI 1.4b does support 120hz on HDMI.

[79wjd]

I think HDMI 1.4b does support 120hz on HDMI.

Everything I've read specifically points out that its 3D 1080p @ 120hz, so I'm really not sure 

[Phillyphries]

djdwosk97, on 13 Nov 2014 - 4:26 PM, said:djdwosk97, on 13 Nov 2014 - 4:26 PM, said:djdwosk97, on 13 Nov 2014 - 4:26 PM, said:

Everything I've read specifically points out that its 3D 1080p @ 120hz, so I'm really not sure 

 

I'm not sure either but if it can output 3D at 120hz, then normal 1080p at 120hz should be a cakewalk, no?

 

Especially since 1080p 3D using framepacking is essentially 1080p x 2 @ 120hz total. Would be a huge disappointment to me if HDMI 1.4b couldn't do 120hz over HDMI

[79wjd]

I'm not sure either but if it can output 3D at 120hz, then normal 1080p at 120hz should be a cakewalk, no?

 

Especially since 1080p 3D using framepacking is essentially 1080p x 2 @ 120hz total. Would be a huge disappointment to me if HDMI 1.4b couldn't do 120hz over HDMI

Well, its sending two signals at 60hz (left and right images) -- 1080p@60hz *2. Therefore non 3D would be the same signal load -- so not a cakewalk. But anyway, the fact that they specifically say 3D, and never say 1080p@.120hz (non-3D) I'm not so sure. 

 

@LinusTech

[Glenwing]

Bandwidth has never been the problem since HDMI 1.3, anything after that has been capable of 3D at 60Hz to each eye (effectively 120Hz, it uses the same bandwidth) the HDMI standard just did not define a 1080p 120Hz mode, so HDMI controllers don't have to know how to handle it.  Sometimes you can hack around it and force it into 1080p 120Hz mode, but it won't work on every display.  Because it's not part of the HDMI spec, HDMI input controllers aren't required to support it, which means no EDID-HDMI handshake for those settings and the display won't report it as a supported resolution to Windows, and so it won't be listed as an option within the OS.  You can try an EDID override and overclock the HDMI pixel clock but it doesn't always work since it's outside the HDMI spec.  It really depends on the display and the quality of the HDMI input controller the display vendor chose to use, some simply won't accept 1080p 120Hz, some will be capable of it (they just don't know it hehe).

 

In short, HDMI 1.3 upgraded the bandwidth enough to support 1080p 120Hz in theory, but the extra is only actually used for 60Hz 3D as defined in the HDMI spec, which is designed with home theater in mind, where no devices output 120Hz so they don't care about officially supporting it.