Inconsistent refresh rate with vsync_adjust=2

[Lisko]

Hi I noticed a strange behavior with some cores on my 4k samsung tv with vsync_adjust=2. When starting some cores like megacd, genesis, neogeo or nes I see the picture flashing twice and in the upper left corner of the screen where it shows the infos on core and display resolution and refresh rate, I see that there is a mismatch between core and display refresh. For example on neogeo the refresh rate listed is 59.6 instead of 59.2 but I can't notice stuttering though. Another curious thing is that if I reset the core using osd then the frequencies will match. Using vsync_adjust=1 the frequencies match with no problem and the picture only flash once during refresh rate switching. What I would want to know is if the problem is only cosmetic maybe related to the odd double switching my tv does with vsync_adjust=2 or if I have to reset the core every time to assure correct refresh rate. Thanks.

[Grabulosaure]

The PLL takes a few seconds to tune when vsync_adjust=2 is selected. During that time frequency is varying a lot and your TV may show incorrect frequency.

Here is an illustration :
https://www.youtube.com/watch?v=veRuXe2wN0g

[DamnBrrd]

Lisko, what is the model of your Samsung 4k tv? It would be useful for other people to know since it looks like it handles vsync_adjust=2 well (after the initial flashing). Thanks!

[Lisko]

Lisko, what is the model of your Samsung 4k tv? It would be useful for other people to know since it looks like it handles vsync_adjust=2 well (after the initial flashing). Thanks!

Samsung QE49Q70RATXZT bought last year.

The PLL takes a few seconds to tune when vsync_adjust=2 is selected. During that time frequency is varying a lot and your TV may show incorrect frequency.

Here is an illustration :
https://www.youtube.com/watch?v=veRuXe2wN0g

Yes, well it's not my TV but the mister itself that shows the wrong frequency. Maybe the code that picks the frequency to be shown needs to wait a little longer for pll to stabilize.

[PikWik]

i have the same TV (Samsung Q70R) and what youre describing is cometic, i get the same double flash starting a core/game when in vsync_adjust=2 and only one flash as it syncs the refresh rate in vsync_adjust=1.

also, one thing ive noticed when in vsync_adjust=2, i dont hear the beginning nintendo bing/sound/tone in the super mario world intro screen if i have vsync_adjust=2 enabled, where if i have vsync_adjust=1 enabled, i hear the beginning nintendo sound/tone everytime.

now at first, i was super concerned with playing with low lag mode on all my games, but after noticing small graphical glitches/tears and weird pixel noise every once in a while, i decided to just enable "match core frequency" and all my games have been glitch free with butter smooth scrolling.

i do quite enjoy being able to play these FPGA cores integer scaled to proper HD on a big screen. while its not a classic CRT in all its analog glory, the trade off of having an HD upscale with gorgeous colors at 1 frame of input lag (my TV's game mode has 14ms of input lag), theres really no reason for me to lug around a smaller TV to play retro games on.

i have a CRT, SNES, and an SD2SNES, and i still prefer to play retro on my mister. FPGA is just that good

[Lisko]

i have the same TV (Samsung Q70R) and what youre describing is cometic, i get the same double flash starting a core/game when in vsync_adjust=2 and only one flash as it syncs the refresh rate in vsync_adjust=1.

also, one thing ive noticed when in vsync_adjust=2, i dont hear the beginning nintendo bing/sound/tone in the super mario world intro screen if i have vsync_adjust=2 enabled, where if i have vsync_adjust=1 enabled, i hear the beginning nintendo sound/tone everytime.

now at first, i was super concerned with playing with low lag mode on all my games, but after noticing small graphical glitches/tears and weird pixel noise every once in a while, i decided to just enable "match core frequency" and all my games have been glitch free with butter smooth scrolling.

i do quite enjoy being able to play these FPGA cores integer scaled to proper HD on a big screen. while its not a classic CRT in all its analog glory, the trade off of having an HD upscale with gorgeous colors at 1 frame of input lag (my TV's game mode has 14ms of input lag), theres really no reason for me to lug around a smaller TV to play retro games on.

i have a CRT, SNES, and an SD2SNES, and i still prefer to play retro on my mister. FPGA is just that good

I just got to your same conclusion. Having already a tv with such a low lag vsync_adjust 2 doesn't add much to 1 mode. I did some simple tests with manual lag test of the 240p test suite and I got the exact same results of about ~2.xx frames with both. My reflexes are already at their limits I suppose and in 1 mode I notice more smoothness too, maybe our tv doesn't like unbuffered mode that much either.