Should I be using Fast Sync?

Solhokuten

Solhokuten

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I already use gsync. Is there any benefit to be had by enabling fast sync as well.
 
it depends. do you want your framerate to exceed the refresh rate of your monitor in order to get faster input response from the game, or do you want perfectly smooth sync all the time? if you aren't you should be capping your framerate at ~158 in order to not incur input lag from gsync.
 
Fast Sync and G-Sync can be used together. G-Sync reduces stutter when frame rates drop below the refresh rate of the monitor. Fast Sync minimizes input lag or latency when frame rates are significantly above the monitor refresh rate.

Most likely the games that benefit from G-Sync (on your computer setup with your settings) are NOT the same games that will benefit from Fast Sync. For Fast Sync to work well, you should be getting FPS of at least twice the display refresh rate. For example, on a 60Hz monitor you want to be getting 120FPS or probably closer to 180FPS to get the most benefit.

The most likely market for Fast Sync is competitive online gamers who typically turn V-Sync Off (for low lag) but want to reduce tearing. Fast Sync doesn't really have tearing, and has similar latency to V-Sync Off. However, at lower FPS (close to refresh rate) it can cause erratic behavior, basically resulting in hitching or jumps in movement.

If you're not sure, it's probably better to not mess with Fast Sync. However, if you play e-sports titles where you can get 200FPS+ and want to stop tearing, then give Fast Sync a try.
 
No, fast sync with g-sync is pointless. The better option is to cap your frame rate at your max g-sync range. So for your monitor, set you max frame rate to 165. With lots of games you can do this in the options or in a config file. For everything else you'll have to use the Nvidia CP.
 
EnhancedInterrogator said:
No, fast sync with g-sync is pointless. The better option is to cap your frame rate at your max g-sync range. So for your monitor, set you max frame rate to 165. With lots of games you can do this in the options or in a config file. For everything else you'll have to use the Nvidia CP.
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do NOT set your framerate cap to 165 with a 165 Hz gsync monitor. when framerate is at or within a few frames of the refresh rate limit of your monitor it begins to act like regular vsync. i haven't used a 165 Hz monitor so i don't know where this exact limit is but on 144 Hz monitors it's at ~138 which is about 96% of max refresh rate, equivalent for 165 Hz would be 158.
 
Odellus said:
do NOT set your framerate cap to 165 with a 165 Hz gsync monitor. when framerate is at or within a few frames of the refresh rate limit of your monitor it begins to act like regular vsync. i haven't used a 165 Hz monitor so i don't know where this exact limit is but on 144 Hz monitors it's at ~138 which is about 96% of max refresh rate, equivalent for 165 Hz would be 158.
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Oh, I did not know that. So yeah, I guess it takes some experimentation to find wherever the limit is, but point remains that you should cap it somewhere.
 
Thanks for all the reponses. It looks like it's best left off on my setup.
 
Odellus said:
. when framerate is at or within a few frames of the refresh rate limit of your monitor it begins to act like regular vsync.
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By the way, what do you mean by this? Do you start to get input delay like you do with vsync? Or do you mean it duplicates frames when you drop below 165, as if gsync wasn't on?
 
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I wouldn't even call it a problem. No matter what display tech you use, you can't update faster than the maximum refresh rate of the monitor (unless you display partial frames aka screen tearing).

With a 165Hz monitor, it is unlikely you are running a much higher frame-rate than the monitor in modern games (in fact, you'd be lucky if you are above refresh rate at all unless on old games or at low resolution). Chances are, most games would run under 165FPS, in that case no lag.

If you are running maybe an old game and are getting crazy FPS (like 300FPS) then you can try Fast Sync, in this case it may actually help to give you input lag similar to V-Sync Off.

If you are somewhere in-between, you're probably safe with G-Sync/V-Sync On. There may be some small amount of lag, in the single ms range that you probably won't notice at all.
 
cybereality said:
I wouldn't even call it a problem. No matter what display tech you use, you can't update faster than the maximum refresh rate of the monitor (unless you display partial frames aka screen tearing).

With a 165Hz monitor, it is unlikely you are running a much higher frame-rate than the monitor in modern games (in fact, you'd be lucky if you are above refresh rate at all unless on old games or at low resolution). Chances are, most games would run under 165FPS, in that case no lag.

If you are running maybe an old game and are getting crazy FPS (like 300FPS) then you can try Fast Sync, in this case it may actually help to give you input lag similar to V-Sync Off.

If you are somewhere in-between, you're probably safe with G-Sync/V-Sync On. There may be some small amount of lag, in the single ms range that you probably won't notice at all.
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huge input lag isn't a problem, haha. thanks for the laugh.
 
FastSync is great for competitive games. If you can notice the difference in smoothness between 144FPS and 300FPS then you should definitely think about it.
 
Oh, from the way Odellus was describing it, I thought it would be more than a frame, or whatever the pre-rendered frame setting is in drivers.

But if it just misses the v-blank, that's not to bad input lag wise. But it could be bad for smoothness, if it results in repeating the previous frame. Is this really an issue with all gsync monitors, they can't operate at their advertised max freesync range?
 
fps lower than hz gsync fixes it

fps higher than hz fast sync fixes it



gsync is varible hz on your screen to accommodate slow fps. this way the gfx card oenst have to stal and wait for the next bus rendering when it "misses the bus" because the "bus" waits for the gfxcard

Fast sync is triple buffer that makes you graficards keep rendering even if both the games buffers are full. aka it not lock up rendering when FPS hits the HZ speed
 
Maybe I'm misunderstanding the problem.

But from what I assume, the amount of lag would be the number of pre-rendered frames (i.e. 1 for V-Sync double-buffer or G-Sync). Meaning 16ms on a 60Hz display, or 6ms on a 165Hz display (like the OP).

If there is something else going on, I'd be interested to understand.
 
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maybe they've fixed it in the newer models, you'll just have to test and see for yourself. definitely is the case for previous gen gsync monitors like the PG278Q.
 
Oh, I remember reading about that now. Yeah, hopefully that's been fixed. Because my instinct, not having that information, would be to cap my frame rate at the advertised maximum frequency.
 
Odellus Interesting. That is more than I would assume, so I guess my assumption is incorrect in this case.

That does look significant. I guess maybe I'm not sensitive to it, as I've never messed with frame capping much or seen the need. Everyone's different.
 
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