Thoughts on Fast Sync Nvidia

[Ricky Omesmo]

hello,
I have been using Fast Sync for a couple of mouths on a 60hz monitor with RTSS limiting at 60fps and I was amazed that I had no stutter at all and felt no delays or fps drops compared to no sync.
But when I made a little research on web about it most of the reviews talk that this technology should only be used when you have at least the fps number 2 times the monitor frequency.

I never really understood why? Could someone give me a hint?

PS: I use RTSS mostly to decrease the temperatures of my GPU since I see no difference on my games by running above the refresh rate.

 

[Deleted member 1560910]

I never heard that. What i know of fast sync is it locks to you monitors refresh and drops all the frames after. It still will show all the frames in the counter. If its not broken dont fix it.

 

[Deathlok664]

no vsync - the gpu renerate the frame and send to monitor. 60 times per second, if the frame is not syncronize tearing apears. (above or below 60hz)

vysnc - sync the refresh rate with framerate, but there's a delay on frames below 60hz. above 60hz, the frames are discarted)

Fast sync work syncronizing the most recent frame with the refresh rate of monitor.
but the frame pacing is not syncronize. so you need 2x refreshrate of the monitor (120fps on 60hz)
you can limit the frame at 60fps. (work like vsync on)
you can limit at 42.9 on nvidia inspector for demanding games below 60fps. (like ghost recon)
fast sync the input lag is less then vsync on below 60fps and there's no tearing above or below refresh rate.
use fast sync only above 120fps or below 60fps with framerate limit at 42.9fps
I use this site for testing, to find the 42.9 magic number, sttutering free. on demanding games.

https://www.vsynctester.com/

the best solution is g-sync. but $$$$

 

[TerryLaze]

Nobody cares about framepacing as long as you can't perceive it,fastsync get's rid of vsyncs input lag and gives you the best performance on a budget.

Also this is not correct:
"Fast sync work syncronizing the most recent frame with the refresh rate of monitor."
Fast sync doesn't sync anything,the only thing it does is to only send completed images to the display,while no sync sends parts of images* which is what creates the tearing.

* it sends a new image even if the previous is not yet fully drawn

 

[Deathlok664]

Nobody cares about framepacing as long as you can't perceive it,fastsync get's rid of vsyncs input lag and gives you the best performance on a budget.

Also this is not correct:
"Fast sync work syncronizing the most recent frame with the refresh rate of monitor."
Fast sync doesn't sync anything,the only thing it does is to only send completed images to the display,while no sync sends parts of images* which is what creates the tearing.

* it sends a new image even if the previous is not yet fully drawn

You are correct. But anyway, fast sync is also best below refresh rate. And high framerates. Just cap the frames at 42.9 for less judder

 

[Deleted member 1560910]

Fast sync doesnt work very well compare to just using vsync off. A higher refresh rate monitor will solve whatever tearing issues you have provided you can produce that fps. If you are only getting 40fps than there isnt a whole lot you can do other than upgrading your hardware