Glenwing

Based on the video format required it may required a certain speed rating, but that's no different than anything else. Hardware will certainly need support, I'm talking specifically about cables.

There is no "special cable" needed for any 3D format on HDMI.

Using conventional LED structures as the pixel elements themselves isn't practical, as they can't just be blindly miniaturized to the level that's needed for the pixel densities a display needs. Some new type of LED designs are needed in order to achieve this. Creation of such "micro LEDs", as mentioned above, is an ongoing challenge which is still in development. As an example, here is a snippet from a recent paper: https://www.mdpi.com/2073-4352/13/7/1001 It's not as easy as "just do what you're doing now, but smaller".

I use the LG 27GL850 which is a few years old model, it doesn't disconnect on power-off over HDMI (but is limited to 100 Hz when FreeSync is enabled over HDMI). There are newer models (27GP850) which don't have this limitation. Haven't used it personally though. If you're shopping on the used market, the first revision of the 27GL850 (with LG logo on the back) that I have doesn't disconnect on power-off on DisplayPort either. The second revision (with UltraGear logo on the back) does however.

Setting scaling percentage uses the full screen resolution. To lower the bandwidth you need to change the resolution itself. GPU scaling will also need to be disabled, otherwise the graphics card will still upscale the image to max resolution before transmitting, and your refresh rate will be limited the options at max resolution. But this isn't always possible, AMD drivers for example don't always handle this correctly right now. It's not good to rely on software to behave. If you can't drive the full resolution it's better to just get a lower resolution monitor.

For DisplayPort, it's inherent to the design. For HDMI it can be designed either way. If yours is designed to disconnect on power off on HDMI too, that's unfortunate. It's common on TVs but usually not on monitors. Anyway, all the 1440p 144 Hz monitors that I know of don't do this on HDMI, only DisplayPort.

That issue is an inherent property of DisplayPort connections, it doesn't have anything to do with FreeSync/G-Sync or HDR. Use HDMI instead if you don't want this behavior.

DisplayPort supports multiple video streams on a single port. Are you mixing it up with HDMI?

Some active cables have bullet points saying that are not compatible with the HP Reverb G2

FYI the general procedure would be this: Refer to the pinned cable guide, select "DisplayPort". https://linustechtips.com/topic/729232-guide-to-display-cables-adapters-v2/?output=DP Opening paragraph: Using linked calculator: https://linustechtips.com/topic/729232-guide-to-display-cables-adapters-v2/?section=calc&mode=maxfreq&H=4320&V=2160 Looks like HBR3 rating will be enough for 90 Hz. So you need a VESA-certified cable rated for HBR3. In this case apparently your headset needs some kind of special treatment, as I see active cables saying this: But without knowing exactly why, it makes it hard to predict what will work and what won't without testing it. This one has a review saying it worked with the G2, but it will need to be paired with a passive HBR3 cable and have an external USB connection for power. https://a.co/d/9wUohw8

Please do not revive an 8-year old thread, just start a new one.

The product page makes it pretty clear it's an LED-backlit LCD (IPS-type). LED-backlit monitors have been commonly labeled as "LED monitors" for over a decade.

HBR3 maximum data rate is 25.92 Gbit/s, which is a physical bit rate of 32.4 Gbit/s. Requirement for 2560×1440 at 240 Hz 10 bpc is 30.77 Gbit/s data rate, which becomes 38.46 Gbit/s bit rate in HBR3 transmission. So it would be outside the limit. But you are comparing the data rate requirement of one against the bit rate limit of the other, which is incorrect If the monitor only supports HBR3, then either it uses DSC, or does not allow 240 Hz and 10 bpc simultaneously. In either case only HBR3 rated cable is needed, anyway.

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There are no specific refresh rate limitations on any interface. HDMI is limited to 144 Hz at 1440p due to its maximum bit rate, if 8 bpc RGB color is used. If the monitor is 1080p, or any of those other things change, the maximum refresh frequency will change.