So I am aware a 60 Hz CRT has 0 - 8 - 16ms of display lag measured from top to bottom. Makes sense. When I measure lag with a photocell tester on my (Panasonic plasma) it is 24ms everywhere => inherent to the panel tech. So in the middle of the screen I am 1 frame behind (24 - 8 = 16). At the bottom half a frame (24 - 16 = 8).
With a 240 Hz QFT-panel, the frame would only take 4.16ms to arrive at the display so the display would be "only" 4ms slower than a CRT? Being 4ms vs 0ms at the top - 12ms vs 8ms in the middle - 20ms vs 16ms at the bottom (rounded obviously).
This would mean that the digital signal path in modern displays is just slower than the analog signal path for CRT's which makes sense again. D/A conversion takes some time. Then there is talk about panels that don't buffer a full frame but immediately output pixel row by pixel row. And talk about matching the panel rate to the cable rate.
How do I know which panels do not buffer? And I read the understanding-display-scanout-lag-with-high-speed-video articel (to which I am apparently not allowed to link to) but I'm not sure I understand what it implies to match or not match cable rate to panel rate.
I assume cable rate is a transmission rate (like bits per second) and you need the source to perform 240Hz transmission rate for a 60Hz frame in order for QFT to work. After all, you want to speed up frame delivery so that your display starts displaying with as little extra delay as possible compared to the analog signal path. It's like with traffic deaths: go for zero
But wait, LG OLED's somehow get down to 1.7 ms of extra input delay with some kind of boost mode. But VRR must be OFF. So it's using QFT without VRR then?
Why am I asking this:
- I have a Mister retro emulator, which supports VRR thus uses QFT?
- I have OG controllers which bypass the USB stack only attributing 1 ms of input lag (SNAC/LLAPI for those who are interested)
- The Mister itself seems to add 2ms of lag (it has to scale the image to 720p of 1080p)
- I am having issues beating challenge 20 dual player on Perfect Dark on the plasma while I have a much higher consistent success rate on my old CRT on original HW.
I'm not sure that last point IS indeed the source of the issue. Playing on a smaller older tv probably makes you have to move the crosshair less distance which may also help:)