TCL 4K 1000Hz monitor

[mackrozhkoff]

Hello, Chief.
Can you tell us any details about this monitor?
Possible release date, panel technology, resolution at which 1000Hz is possible (dual-mode display?), your impressions of it, and more.
I was interested in the upcoming 1440p 480Hz LED panel, but this TCL confused me.

[Chief Blur Buster]

I have no data -- TCL was extremely tight lipped about this prototype. I wasn't yet allowed to run TestUFO.

However, DisplayWeek exhibited 500-600Hz displays last year that were genuinely tested by TestUFO, so I have no reason to doubt that this was somehow achieved, though the cable bandwidth is an issue. You'd need 3xDSC at 4:2:0 chroma, or one of those auto-reduced-resolution-modes (much like the 480Hz 1080p modes in some 4K 240Hz OLEDs), but TCL didn't tell me yet.

Nontheless, DisplayWeek tends to be a fairly honest convention between insiders (it's an "industry internal" convention that includes R&D/engineering folks, rather than a "for press" convention like CES or E3). I presume I would have had to be a bigger vendor interested in large quantities for me to sign an NDA accessing the specs.

My biggest question is indeed about cable bandwidth, since latest cables can't sustain 4K 1000Hz uncompressed or 4:4:4 yet.

480Hz OLED will have clearer motion than 1000Hz LCD. Keep this in mind the LCD GtG penalty on refresh rate.

[mackrozhkoff]

Thank you for your answer, Chief.
Probably the best option for me is to wait for the 1440p 480hz OLED if even the newest 1000hz LCD panel cannot compare with it in terms of motion clarity.

[Chief Blur Buster]

Obviously it depends on your priorities! Depending on panel technology, 4K 1000Hz will have line-item advantages (e.g. pollrate sync to 1000Hz mice, possibly lower latency by only 1ms, etc) but won't always win against 1440p 480fps. Especially since OLED pixel response is so scarily fast.

Now personally the GPU technology favours 480fps 1440p, it's much easier for me to run games at 1440p 480fps.

[thatoneguy]

480Hz OLED will have clearer motion than 1000Hz LCD. Keep this in mind the LCD GtG penalty on refresh rate.

Won't this depend on the GtG figures? Isn't there 0.5ms GtG LCD monitors already?
For example 0.5ms GTG + 1ms MPRT > 0.03ms OLED response + 2.08ms MPRT

[Chief Blur Buster]

480Hz OLED will have clearer motion than 1000Hz LCD. Keep this in mind the LCD GtG penalty on refresh rate.

Won't this depend on the GtG figures? Isn't there 0.5ms GtG LCD monitors already?
For example 0.5ms GTG + 1ms MPRT > 0.03ms OLED response + 2.08ms MPRT

Haha....

Are you aware GtG standard only partially measures GtG?

0.5ms GtG(10%-90%) is still often 10ms GtG(0%->100%)
VESA GtG cutoffs miss 20% of the curve that takes much longer than the 80%, I can still see a 10% dark gray in the midst of a white-to-black transition.



OLED does not do this, and to my eyes, 240Hz OLED is clearer than 360Hz LCD, and 480Hz OLED is way clearer than 600Hz LCD prototype that I saw. So much, that I confidently (bet-your-mortgage, email me) make the prediction that 1000Hz LCD (VA or IPS) will still have a bit more ghosting/blurs than 480Hz OLED. OLED are pretty near-perfect followers of Blur Busters Law.

For more information why VESA chose cutoffs (good legacy reason, obsolete today)
https://www.blurbusters.com/gtg-vs-mprt

Also check out RTINGs new motion blur measurement metric that shows some LCD colors are 10x slower than others:
https://www.rtings.com/monitor/tests/mo ... -deviation

So one color measures 0.5ms but a different color measures 5ms. Very common on LCDs.
And spoiler, that's just merely GtG90%.

However.... 1000Hz LCD (even with more motion blur) can still have latency advantages over 480Hz OLED, depending on whether the 1000Hz LCD can realtime scanout the signal (stream the pixels to panel like current esports panels, even before the 1000Hz signal is received over cable), without full-framebuffering before refreshing the panel (like OLEDs usually currently have to).

[thatoneguy]

*snip*

Is this the case with Quest 2/3 too? I thought those were using some faster switching LCDs.
If it's the same case with Quest 2/3 then LCD is toast for Sample and Hold.
Only way I could see 1000hz LCD being viable now is with strobing to hide the GTG transitions(in exhange for some lag).
Maybe they should just stop with LCDs.

[Chief Blur Buster]

*snip*

Is this the case with Quest 2/3 too? I thought those were using some faster switching LCDs.

Apples vs bananas.

Quest 2/3 is strobed.

I wasn't talking about strobed LCDs.

When I compared non-strobed 1000Hz sample hold LCD versus 480Hz sample and hold OLED I meant flickerless sample-and-hold 1000Hz LCD versus flickerless sample-and-hold OLED -- with no BFI and no strobe backlight.

The impulsing method for LCDs is backlight flashing, and OLEDs is black frame insertion. They achieve the same end goal (in theory). LCD is throttled by crosstalk (GtG0->100% longer than a refresh cycle), while OLED is throttled by refresh rate limitation (since BFI has to be delivered like a refresh cycle to a non-PWM-driven OLED)

Also...The art of a strobe backlight is "Cram LCD GtG In The Blanking Interval In Total Darkness Between Strobe Flashes". Strobe crosstalk is the remnant LCD GtG unfinished by the time the backlight flashes again. But Quest 2/3 achieves nigh near perfect zero crosstalk, due to superlative overdrive tuning.

Quest 2/3 are impulse-driven LCDs (strobe backlight) with giant-budget (Facebook $$) overdrive tuning that managed to squeeze LCD GtG into the dark period of a strobed refresh cycle.

At 90Hz and 0.3ms pulse width flash (1/90sec = 11ms) that gave Facebook a budget of up to ~10ms to try to hide LCD GtG0%->100% in total darkness between LCD scanouts. In reality, no LCDs can global-refresh, so you have to subtract scanout latency from that. Faster scanout latency (from large VT's or QFT) can give more time for LCD to settle in total darkness before being flashed visible. Quest 2/3 alsouses an internal variant of the Large Vertical Total trick (bottom of www.blurbusters.com/xg2431 ...) to create a large VBI, as LCD GtG is initiated on last pixel in a time-delayed offset relative to LCD GtG on first pixel (high speed videos at www.blurbusters.com/scanout ...) -- not all pixels refresh at the same time, and that's a problem for global strobe flash. However, the problem was solved on Quest 2/3, completely hiding the LCD GtG in total darkness between flashes.

As a reminder to forum readers (for squarewave GtG=0 displays impulsed versus sample-and-hold):



- Eye tracking motion blur is frametime on sample and hold (flickerfree).
- Eye tracking motion blur is pulsewidth on impulsed (strobed).

[mackrozhkoff]

Thanks for your answers, Chief.
They are very detailed, and therefore a lot of things become clearer.