XH90: how is 120 Hz going to work on a 100 Hz panel?

[yurijgera]

Hallo, I got XH9077 connected via HDMI 2.0b to GeForce 1080Ti.
Im pretty happy with the image quality and the software, but I got a question regarding the 120 Hz feature.

According to Sony press release (https://presscentre.sony.de/pressreleases/der-neue-4k-hdr-full-array-led-fernseher-xh90-von-sony-ist...) it got a 100 Hz panel:

- Einzigartige Bewegungsschärfe und flüssige Bilder mit X-Motion Clarity Technologie und 100 Hz nativem Panel selbst in schnellen und actionreichen Szenen

According to Sony Technical Specifications (https://www.sony.de/electronics/fernseher/xh90-series/specifications😞

4K120 support through firmware update.

HDMI™ Signal: 4.096 x 2.160p (24, 50, 60 Hz --> where are 120Hz ??? <--), 3.840 x 2.160p (24, 25, 30, 50, 60 Hz), 1.080p (30, 50, 60, 100, 120 Hz), 1.080/24p, 1.080i (50, 60 Hz), 720p (30, 50, 60 Hz), 720/24p, 576p, 480p

I don't get it. The TV is advertised with 4K120 (via update), but specifies 4K HDMI Signal max 60Hz only, uses a 100 Hz panel...  How is it going to work, once true HDMI 2.1 GPUs become available? If GPU sends 4K@120Hz, how is Bravia going to display that on a 100 Hz Panel? Will it just trow random frames away? Will it interpolate and introduce additional >10ms lag required for the interpolation?

[Peter_S.]

Hi yurijgera,

to my knowledge "X-Motion Clarity" is calculating new frames (guess interpolation) according to the input signal.

So it doesn't just drop frames but adopts the current frames to new ones.

Unfortunately I do not have all the technical detail for this technology.

Cheers

Peter

[yurijgera]

Peter, thank you for the clarification.

I have one more question:

The TV should support 1.080p 100 and 120 Hz according to its HDMI Specification.

Today I replaced my old HDMI cable with a new HDMI 2.1 48Gbps one and wanted to try 1080p at high refresh rates out.

But in Windows 10 and Nvidia control panel the highest refresh rate offered is 60Hz.

The TV is shown as "Generic PnP Display".

My GTX 1080Ti supports only HDMI 2.0b, but that should work fine with 1080p@120.

How can I get the 100 or 120 Hz on a PC?

Edit:

OK, in Nvidia control settings I can edit and add custom resolutions:

Tried 100 Hz first, but the TV seem to have some kind of issue with that:

Then I tried 120 Hz and it worked, even with HDR! At 120Hz the Windows desktop feels so much smoother. I am totally amazed. Will never go back to 60 Hz again.

Now waiting for you guys to release the long awaited 4K@120 Hz firmware update

One thing I don't quite unterstand. In the EU the panel supposed to be a 100 Hz one, but 100 Hz does not seem to work, only 120 Hz. So Im confused. Is it really a 100Hz panel here? Or a 120 Hz one?

Edit2:

Here https://en.tab-tv.com/?p=14466 I read that "There is no difference between TV support of 100 hz or 120 Hz". It seem that all 100/120 Hz panels are in fact 120 Hz panels. Marketing simply advertises them as "100Hz" in the EU and "120" Hz in the US. Quite confusing. So I hope my TV will not be interpolating anything in case of native 120 Hz signal input.

[yurijgera · Accepted solution]

Since Windows 10 Build 2004 the 1920x1080@100 and 120 Hz resolutions can now be selected in display settings.

This thread can be closed as resolved.