Discussion in 'Article Discussion' started by bit-tech, 9 Jan 2019.
Seems whoever certifies the monitors is doing so in alphabetical order, they only went through the A and B.
I suspect, but not sure, that the GSync compatible monitors require them to be LFC capable, and then maybe more. GSync has it's version of LFC by default, AMD left Freesync 1 up to the manufacturers and said do what you wish. Freesync 2, IIRC, however be LFC capable.
There's also been a change in the LFC range, originally it was >2.5 times the lower frequency, now I think it's just 2 times. Though as I've been discussing on OCUK with my issues with LFC, it may require VSync to be on for it to work. *shrugs*
I don't think there's such a thing as a LFC monitor, low frame rate compensation basically inserts extra frames if, or when, the FPS being rendered by the GPU falls below the capabilities of the monitor, with G-Sync those extra frames are inserted by the module within the monitor (presumably by reissuing the last frame stored within its own buffer), with FreeSync that reissuing of a frame is done by the GPUs own frame buffer, at least that's how i think i remember reading about how it worked.
IIRC The 2x - 2.5x thing is more to do with if you can use LFC, if the maximum refresh rate isn't 2.5x - 2x the minimum then LFC can't be used/won't work, and VSync works (iirc) the same as it normally does, with it on you get no tearing/judder when going under the minimum and with it off you do..
Screen tearing happens when the GPU is pushing the game out at a framerate that exceeds the monitor refresh rate, it does however nothing to address the stutter / judder / jerking (in fact it makes it worse) when the GPU is pushing the game out at a framerate that is below the monitor refresh rate.
Due to that you should not use VSync if the min framerate isn't at least equal to the monitor refresh rate.
At least with Nvidia cards (no clue if there is an AMD equivalent) there is a solution, Adaptive VSync, turn that on once in the Nvidia control panel and you'll be fine, as Adaptive VSync caps the FPS at the monitors refresh rate (thus eliminating tearing) without introducing the problems regular VSync has at low framerates.
However while Adaptive VSync doesn't introduce extra problems at low framerates it also does nothing to fix any and thats where GSync and Freesync come in to play.
IDK, that's not how AMD says it works when going under the minimum refresh rate of the monitor (link to LFC PDF at the bottom)
Link to Nvidia saying tearing is from FPS being higher than what the monitor can handle:
Yes but the same applies with any attempt to refresh the display part-way through, be that refreshing sooner or later than its typical cycle time, all Vsync does is attempt to match how many frames are being sent to the monitor per second with how many it typically displays, if you enable Vsync that means you're telling the framebuffer to only send, for example, 60 frames every second.
If your GPU can't render 60FPS and you've set Vsync on then you get judder as you'll only be sending 30FPS, the next lowest available division of 60, if you've set Vsync off the frame is sent when ready, even if that's part way through a screen redraw and you get whatever FPS your GPU is capable of rendering along with tearing.
All LFC does is send extra frames to the monitor so what would have been 30FPS becomes 60 with Vsync on and what would've been whatever your GPU is capable of rendering is doubled.
Having just checked apparently they do so that sort of makes everything i said rather pointless.
I was hoping the extra bandwidth and RAM might turn Vega 7 into a 4k beast. Seems not
Only with single-buffer operation, which anybody still using should be extremely embarrassed about: triple-buffering has been common knowledge for well over a decade. The point is moot (for Nvidia at least) because Fast Sync is driver-level triple-buffering you can apply to any game, so you should never see tearing above or below the refresh rate.
From what I can see, Freesync goes down to 9Hz, G-Sync goes down to 1Hz (Although G-Sync "compatible" doesn't go this low.)
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