G-Sync, as far as I know, had virtually no impact on FPS. G-Sync helps to reduce screen tearing and ghosting. It also will make any fluctuation in FPS look smoother.
It's difficult for the human eye to notice a difference between 144 Hz and 240 Hz. As such, 240Hz monitors won't appeal to the average person, but if you can see the difference and you find that it helps you perform better in games or just makes them more enjoyable, then a 240Hz monitor will be well worth the expense.
If you are playing fast paced games such as FPS games or racing games then yes, G-Sync might be worth your time. If your GPU is producing 200fps on Fortnite, but your monitor is only a 144hz monitor, then G-Sync isn't going to stop all the tearing because your frame rate is above your monitors refresh rate.
So to answer your question, YES there is a difference between a 144hz monitor with and without GSync. If your monitor does not have GSync and your GPU is unable to produce 144FPS, you will notice tearing.
I guess, the core difference between Nvidia's G-Sync display technology and AMD's FreeSync is that G-Sync is a closed technology, which means that in order to get it, you need to go to Nvidia for the special hardware which is and can only be developed by them, thus increasing the price point of the hardware.
It's worth noting while G-Sync locks the frame rate to the upper limit of the monitor Freesync can bypass this and give you higher frames. This would result in some tearing as your frame rate and refresh rate wouldn't match but would keep input lag very low.
Well, according to G-Sync does not affect performance in games. It does not add extra input lag nor other performance hits.
Turning Gsync on is actually causing frametime spikes and fps drops. Leaving every other setting exactly the same and just changing the gsync on / off produces these stutters 100% of the time.
G-Sync operates within the monitor's refresh rates, so that means lower FPS, and it introduces a small amount of input lag*, so it's not an option for most pros. G-Sync's point is to make games more enjoyable by reducing stutter, getting rid of vsync input lag, and eliminating tearing at the same time.
Should I Turn GSync On or Off for Valorant? Generally, Valorant is already optimized for the highest possible frame rates, and GSync only improves individual cases. The sync of refresh rates and frame rates causes input lag, which has a much more negative impact on performance than occasional screen tearing.
Now, any 10 series Nvidia graphics card and above that's capable of supporting G-Sync as standard can benefit from FreeSync panels, enabling the feature in the monitor's settings.
FreeSync on Xbox consoles does need to be enabled in the dashboard settings as it does not automatically switch on even when connected to a compatible FreeSync display. The PS4 does not support VRR but the PS5 can support the feature through its HDMI 2.1 port. However, Sony hasn't activated the feature yet.
No pro use G-Sync or Freesync.
If the Setup G-Sync option doesn't appear after you've performed the above steps, go to the 3D Settings field, and click Global. Scroll down to Monitor Technology, and choose “G-Sync Compatible.†That's it! You can now run G-Sync on your FreeSync monitor.
