4K Sony 120HZ tv only 60HZ

[Kyle_James]

Butchered old question... but I can only find older posts about it so here it is:

I purchased a Sony 4k TV last year, even before I built my gaming PC. I understand the difference in the older LCD displays, they are all 60hz but scale to 120-240hz through the motionblur/software in the TVs computer.
The question is have they changed? I was told when buying the 4K tv that it was a 120HZ native TV. With research nothing really comes of it, or talks about it. I found its input lag at 23ms and that was good enough for my Ps4 at the time. Now that I have two gtx 1080s, I sometimes will unplug my Gsync 1440p monitor and try out some old TV gaming @ 4K, but I only get 60HZ
Yes it is an HDMI 2.0 and I was told it only outputs 60hz, but If I was to use a DVI-D to HDMI would I achieve that 120hz? Does anyone have any experience with 4k PC gaming on a TV?

Thanks!

 

[joex444]

http://www.pcadvisor.co.uk/feature/digital-home/displayport-vs-hdmi-whats-difference-3535257/

DP 1.2: 3840x2160@60Hz; 17.3Gbps max

HDMI 2.0: 3840x2160@60Hz; 18Gbps max

HDMI 1.4: 3840x2160@30Hz; 10.2Gbps max

Reason: 3840x2160x24x60 = 11,943,936,000. What's that? The bandwidth in bits/sec. It's 12Gbps. The 24 is 24-bit color depth.

Now native 120Hz would be 3840x2160x24x120 = 24Gbps. This is more than HDMI 2.0 or DP 1.2, and we've clearly seen that HDMI 1.4 is limited to 10.2Gbps which can't do 4K60 so it does 4K30.

Meaning... there's no connection that exists which can handle the bandwidth necessary for native 120Hz 4K. Which is exactly why I would suggest you double check to make sure Sony really says it's native 120Hz and would truly support a non-existent 120Hz 4K input.

 

[photonboy]

Hi,

The input to the HDTV is 60Hz.

If you choose "120Hz" mode this is for artificially creating smoothness by analyzing several frames then creating a FAKE frame for every normal frame which sits in between the first and second true frames.

This is again, AFTER the video is input into the HDTV.

*It is also something you should NOT enable for gaming as the increased delay creates a lag when gaming.

You COULD enable this but the PC is not aware of the post-processing, is still outputting a 60Hz signal so that is what is reported on the screen (even though the screen is refreshing at 120x per second with all 120 frames being unique).

Summary:
- can not input more than 60FPS (full frames)
- should NOT enable motion smoothing (except for sports videos)

 

[photonboy]

Update:

"Native" 120Hz only means the TV can refresh the screen 120x per second. It's not impossible that it is capable of 120Hz input but I doubt it (or if so, probably at 1080p only), and as said there is currently no hardware support for inputting a 4K, 120Hz signal anyway on the PC side I believe.

I would also add that getting the benefits of 4K is difficult. You must sit close enough to benefit which is roughly anywhere closer than 1.5X the HDTV's diagonal.

You are usually much better off sticking with a solid 1080p, 60Hz input. Don't take my word for it though, and of course the nature of the game may make SCALING better or worse for some titles (it's complicated).

Finally, you could not output 120FPS at 4K anyway (in terms of video games usually) so it's arguably a moot point.

 

[Kyle_James]

Thanks guys, probably bought into 4K a little early. Monitors ftw.

 

[trickyt57]

I bought a Philips 43PUS6551 UHD 4K television to use as a computer monitor. According to the specifications it should run at 60 Hz when in 3840 X 2160 resolution. However at that resolution my Mac says the Refresh Rate is a choice of 24 HZ, 25 Hz or 30 Hz. I therefore can't get 60 Hz.

The Avinity HDMI cable I am using says "This cable supports the HDMI 2.0 specifications". It's 1.5m, pure copper suitable for 18.2 Gbps, and 4K/ultra HD.

The TV manual reads as follows:
"Display Input Resolution
Video formats
Resolution — Refresh rate
• 480i - 60 Hz
• 480p - 60 Hz
• 576i - 50 Hz
• 576p - 50 Hz
• 720p - 50 Hz, 60 Hz • 1080i - 50 Hz, 60 Hz
• 1080p - 24 Hz, 25 Hz, 30 Hz
• 2160p - 24 Hz, 25 Hz, 30 Hz, 50 Hz, 60 Hz
Computer formats
Resolutions (amongst others)
• 640 x 480p - 60 Hz
• 800 x 600p - 60 Hz
• 1024 x 768p - 60 Hz
• 1280 x 768p - 60 Hz
• 1360 x 765p - 60 Hz
• 1360 x 768p - 60 Hz
• 1280 x 1024p - 60 Hz
• 1920 x 1080p - 60 Hz
• 3840 x 2160p - 24 Hz, 25 Hz, 30 Hz, 50 Hz, 60 Hz"

I have tried all the TV settings I can find e.g. Game mode, Computer mode, Personal mode, but can't seem to get the monitor into 60 Hz refresh rate at the 4K resolution. (I have another monitor on the same Mac running at a max resolution of 2560 X 1440 with a 60 Hz refresh rate.)

Any ideas on how to get the 60 Hz refresh rate would be most welcome. The Philips Manual located here does not cover it. http://

 

[Kyle_James]

This happened with my dads PC, He bought a sharp 4k cheap tv and it took a crazy amount different cable attempts and messing with the resolution and HZ in the nvidia control panel. We ended up settling for a Belkin 4K (true 4k) supported HDMI cable. Was around 45USD

 

[trickyt57]

I read somewhere that older macs can't do the 60 kHz refresh rate at the high-resolution. I have the same problem with my mac and a large tv monitor of 43 inches. I have given up trying to fix it.

 

[neohulk]

http://www.pcadvisor.co.uk/feature/digital-home/displayport-vs-hdmi-whats-difference-3535257/

DP 1.2: 3840x2160@60Hz; 17.3Gbps max

HDMI 2.0: 3840x2160@60Hz; 18Gbps max

HDMI 1.4: 3840x2160@30Hz; 10.2Gbps max

Reason: 3840x2160x24x60 = 11,943,936,000. What's that? The bandwidth in bits/sec. It's 12Gbps. The 24 is 24-bit color depth.

Now native 120Hz would be 3840x2160x24x120 = 24Gbps. This is more than HDMI 2.0 or DP 1.2, and we've clearly seen that HDMI 1.4 is limited to 10.2Gbps which can't do 4K60 so it does 4K30.

Meaning... there's no connection that exists which can handle the bandwidth necessary for native 120Hz 4K. Which is exactly why I would suggest you double check to make sure Sony really says it's native 120Hz and would truly support a non-existent 120Hz 4K input.

Hi, by that same calculation, it should be possible to do 1080p gaming at 120hz (1920x1080x24x120 = 5.9Gbps, well within the 18Gbps possible on HDMI 2.0). Would that be correct? TIA.