thatoneguy wrote:What about a combination of G-Sync and BFI then?
That's what I already wrote about.
Black frames are achieved by turning off the backlight.
If you mean actual black frames (empty black pixels), that's a terrible technique.
It will halve the maximum GSYNC rate, because it takes 1/(Max)th of a second to transmit and display frame to the display. For a GSYNC display range from 30Hz thru 144Hz, it takes 1/144th to transmit & scan the display. The display paints top-to-bottom (like http://www.blurbusters.com/lightboost/video
....) in a finite time period. Think of the display screen behaving like a high-speed-fax machine -- metaphorically, the display cable is transmitting 144 faxes per second -- and displaying them sequentially in a top-to-bottom scan that is so fast you don't notice the scan effect -- it takes a finite amount of time to transmit the image (one refresh cycle) over the cable and display onto the LCD in realtime -- beginning with the top edge of the image and progressively-scanning the remainder to the bottom edge, like a printer or a fax but in 1/144th of a second (minus VSYNC blanking interval time -- metaphorically like the VHOLD black bar on a malfunctioning 1970s analog TV with a rolling picture -- that is like a page break between fax pages -- aka refresh cycles -- the time length of a VSYNC blanking interval is usually about half a millisecond at default vertical total during 120Hz+) -- you can see the top-to-bottom scan effect in the high-speed video that I made several years ago, http://www.blurbusters.com/lightboost/video
And since you're painting a black screen top-to-bottom on the screen inn 1/144sec (for a typical 144Hz GSYNC monitor), you're also forcing the NEXT refresh cycle to *wait* for the black frame to finish painting, before the next visible refresh can be displayed.
There's a reason why black frame insertion via black screens (black-pixels-on-LCD) is possible only at half the refresh rate of the display (or less) -- http://www.testufo.com/blackframes
(my animation of software-based black frame insertion) -- it is as time-inefficient and bandwidth-inefficient as trying to transmit a completely black fax page between fax pages!
So, the best way to do black frame insertion is via turning off the backlight (same thing for human eyes, but much faster to do, simpler, cleaner and, no wasted bandwidth, no reduced refresh rate limit, and less lag. Even if not perfect, still far better.)
And strobing is much more efficient, on a power basis. No black pixels to block backlight. And you can strobe the backlight much brighter (usually 3x-5x) to compensate for the backlight-off time.
To the human eyes, "black frames" is simply blackness -- whether by LCD black pixels -- or via backlight-OFF -- and doing it via turning off backlight is MUCH more efficient, much less lag, much better color, much clearer motion reduction, does not waste cable bandwidth, does not delay display's ability to diplay the next refresh, you can vary the length of the black frame much more perfectly (e.g. strobe flash length), etc.
Some emulators (e.g. this MAME
) use software-based black frame insertion to convert 120Hz LightBoost/strobing into 60Hz strobing via inserting black refresh cycles between the emulated refreshes, for a full 60Hz zero-motion-blur CRT clarity effect, for displays whose stroberate cannot be reduced to as low as 60 flashes per second. But it is better if hardware is able to do 60Hz single strobe (e.g. BENQ XL 2720Z)