Variable refresh rate, or VRR, has been one of the coolest pieces of tech to grace our
PCs over the past decade. Before VRR, you can have really ugly screen tearing, even with a high-end graphics card.
But VRR has largely eliminated this problem for gamers with recent hardware.
However, there's been a lot of confusion over what exactly VRR does and how it works,
so let's get right down to explaining it. The basic premise of VRR is rather simple.
It matches up your monitor's refresh rate, or how many times per second it's showing
you a new image, with the frame rate of your graphics card.
Traditionally, monitors would run at one constant refresh rate, say 60 times per second, or
60 hertz. But your GPU's frame rate would swing considerably depending on how hard it had to work to render
the action in the game you're playing at that moment.
This mismatch would often result in tearing, where your monitor would essentially try to
display multiple frames at once because the GPU has fed it a new frame in the middle of
a refresh cycle. The historical solution to this problem was to use a feature called Vertical Sync, or
V-Sync, which would lock your graphics card's frame rate to your monitor's refresh rate.
However, if your GPU's frame rate falls below your monitor's refresh rate, vertical
sync can cause stuttering, as the GPU isn't finished rendering the next frame yet.
VRR adjusts what your monitor is doing instead, making it a very attractive solution.
While it is still possible to get tearing if your frame rate exceeds your monitor's maximum
refresh rate, this can typically be solved by setting an FPS cap in your game settings.
But not all VRR is created equal, as there are several different kinds of VRR buying
for your attention. There's Vesa Adaptive Sync, which is an open source flavor of VRR that works on a driver
level. AMD has FreeSync, which is really just Adaptive Sync that AMD has tested and put their stamp
of approval on. Then there's NVIDIA, who has a group of solutions under the G-Sync umbrella.
G-Sync, on its own, is a proprietary solution consisting of extra NVIDIA hardware built
into the monitor to handle VRR processing.
The term G-Sync-compatible, on the other hand, refers to an Adaptive Sync screen without
extra NVIDIA hardware on the display, but that was tested by an NVIDIA to confirm it
works well, similar to AMD's FreeSync. At the top of the NVIDIA food chain is G-Sync Ultimate, which includes fancier monitors
with better HDR support, along with that special NVIDIA hardware built in.
Compatibility is better than it used to be in that newer G-Sync displays that have the
extra hardware can now work with non-NVIDIA graphics cards, even though this wasn't always
the case. And the various flavors of Adaptive Sync should work on most modern GPUs.
And VRR is part of the HDMI 2.1 spec and works similarly to Adaptive Sync, which is more
of a DisplayPort thing. VRR can be susceptible to motion blur or ghosting.
Although this problem is not unique to VRR, the issue is that displays can have a harder
time compensating for it when VRR is enabled.
You see, pixels have what's called a transition time to change from one shade of
gray to another. And even though we use color monitors, we're talking about shades of gray because the actual
light usually passes through a color filter to create the final image that you see.
Anyhow, pixels are driven a certain amount so that they'll transition in a way that
looks correct. When your refresh rate is changing so often with VRR, you'll also have to change the
amount that you drive the pixels. And this can be tricky.
If you don't do it, or don't do it right, blurring or artifacting can occur.
VRR displays compensate for this by driving pixels a different amount or over-driving
them depending on refresh rate. Determining the correct amount of overdrive requires extra processing and larger lookup
tables which store the correct values the display should be using.
Which brings us back to G-Sync. Monitors with G-Sync hardware inside tend to do a better job with this extra processing
and give you an image with less motion blur. That's why the extra hardware.
Now of course, we're not endorsing NVIDIA or telling you to go out and spend extra
money on a G-Sync monitor. If you care more about preventing screen tearing and ghosting blur isn't something you typically
notice, you might be completely happy with an adaptive sync monitor that'll cost you
less money. Now if you'll excuse me, I gotta tear out of here.
So thanks for watching guys, if you liked this video, you might also like our video
on pixel cleaning. How does your OLED not burn in?
What does that setting do? What is it? Check it out.