Hello Pittyh,

All i know is that club3d is working on it there is no date set when it comes out. might be Q2 or Q3.

as soon as it is available it will be announced on the club3d website.

Stay tuned 🙂

Thanks,

Although, I’ve read displayport 1.4 is only capable of 28gps? so not sure if it would even work now. with hdmi2.1 4k120fps probably being more than 28gps?

Hello Pittyh,

I am not aware of 28gps, i think you mean Gbit/s. GPS stands for global positioning system, not part of club3d their portfolio.

The allocation of displayport is as follows:

The maximum bandwith is set on 32.4Gbit/s

The maximum data rate is set on 25.92Gbit/s

Yes I missed a b in there, quite a few times. My bad.

Anyway my point is the difference between bandwidth of hdmi 2.1 and displayport 1.4 may cause some limitations as to what resolutions/colour depth can be transported.

Could 4k 120hz with HDR even work?

Hi pittyhm

thank you for refraising your question. Displayport 1.4 is able to put out 8k@60hz hence it is able to put out 4k@120hz

Hdmi 2.1 is able to match these specifications with 8k@60hz and 4k@120 

the color output on both will be 4:4:4

for indept reading i would like to refere you to VESA and HDMI

https://vesa.org/featured-articles/vesa-publishes-displayport-standard-version-1-4/

https://www.hdmi.org/manufacturer/hdmi_2_1/index.aspx

Club3d Cables are certified by these standarts.

DisplayPort 1.4 only supports 25.92 Gbps of data (50% more than DisplayPort 1.2) but has Display Stream Compression (DSC) which is required for 8K 60Hz 8bpc (RGB or 4:4:4).

HDMI 2.1 supports 42.667 Gbps and can achieve 8K 50Hz 8bpc (RGB or 4:4:4) without DSC (60Hz requires DSC). HDMI 2.1 also supports DSC though, so it can go much higher than DisplayPort 1.4.

HDR uses 10bpc.

So even though the bandwidth of HDMI 2.1 is greater than DisplayPort 1.4 (only by 65%) an adapter to convert one to the other (including DSC on both ends) would still be useful.

Is it possible to create an HDM 2.1 display that doesn’t support DSC? If so, then it would be useful for a DisplayPort 1.4 to HDMI 2.1 adapter to tell the computer that it supports DSC, then uncompress the output to the HDMI display.

Well if you can belt one of these out quickly enough before the video card manufacturers release hdmi2.1 cards, you might sell a few.

I would buy one.

I would also buy one definitely. and a few friends of mine too.

I use a 4k LG sm9500 on pc, and it has full hdmi 2.1 ports.

My few concerns though are :

• We have no proof yet that the LG hdmi 2.1 are actually fully working, ( unless Club 3d or realtek has been testing their cables on those )
• A complex adapter like this would probably create some input lag ? or not ?

An adapter would work on the pixel level, rather than the frame level so there shouldn’t be any lag. For 4K 60 Hz: A frame is 60 Hz or 16 ms. A line is 133 kHz or 8 µs. A pixel is 533 MHz or 2 ns.

I’m not sure how much information is required by DSC. The DSC specs are freely available though. There is C source code so you can test it with various images. VESA describes DSC as a low latency, low complexity codec. Wikipedia says that for HDM 2.1, DSC is only for resolutions higher than 8K but that doesn’t mean an adapter couldn’t use DSC on the DisplayPort side.

I don’t know how an adapter will handle other features of HDMI 2.1 such as VRR (maybe convert it to DisplayPort’s Adaptive Sync?)

Most of the lag will probably come from the TV instead of an adapter. According to https://www.rtings.com/tv/reviews/lg/sm9500 , it has 13 ms input lag for 60 Hz game mode. For 120 Hz it’s 7 ms. Outside game mode, it’s up to 84 ms.

New cables will not be enough to test HDMI 2.1. You’ll also need a HDMI 2.1 source. AMD and Nvidia don’t support it yet so this is where an adapter would be useful.

   It  looks like there is a race between Club 3d and Realtek on this, the fact that it takes time shows that its either a very complicated task, or there is some kind of pressure out there from various companies not to allow 4k 120hz on tv yet.

   Think about it, if today we could get our 4k tv to get 4k / 120 Hz / full 4:4:4, with VRR and low input lag ( 6 – 7 ms ) ,   then Tvs would become better than Pc monitors for gaming.

   On top of that, if this Club 3d or Realtek adapter work, then we would not bother buying a RTX3080ti or NAVI next gen. that will be out mid 2020 i guess.

It would be great to have an estimation for this adapters release date.

The CAC-1085 is a DisplayPort 1.4 to HDMI 2.1 adapter. For USB-C to HDMI 2.1 see https://insights.club-3d.com/thread/usb4-to-hdmi-2-1/