1 00:00:00,000 --> 00:00:04,640 Variable refresh rate, or VRR, has been one of the coolest pieces of tech to grace our 2 00:00:04,640 --> 00:00:12,000 PCs over the past decade. Before VRR, you can have really ugly screen tearing, even with a high-end graphics card. 3 00:00:12,000 --> 00:00:16,360 But VRR has largely eliminated this problem for gamers with recent hardware. 4 00:00:16,360 --> 00:00:21,680 However, there's been a lot of confusion over what exactly VRR does and how it works, 5 00:00:21,680 --> 00:00:26,240 so let's get right down to explaining it. The basic premise of VRR is rather simple. 6 00:00:26,240 --> 00:00:30,040 It matches up your monitor's refresh rate, or how many times per second it's showing 7 00:00:30,040 --> 00:00:33,400 you a new image, with the frame rate of your graphics card. 8 00:00:33,400 --> 00:00:39,240 Traditionally, monitors would run at one constant refresh rate, say 60 times per second, or 9 00:00:39,240 --> 00:00:45,840 60 hertz. But your GPU's frame rate would swing considerably depending on how hard it had to work to render 10 00:00:45,840 --> 00:00:49,040 the action in the game you're playing at that moment. 11 00:00:49,040 --> 00:00:53,920 This mismatch would often result in tearing, where your monitor would essentially try to 12 00:00:53,920 --> 00:00:59,120 display multiple frames at once because the GPU has fed it a new frame in the middle of 13 00:00:59,120 --> 00:01:05,440 a refresh cycle. The historical solution to this problem was to use a feature called Vertical Sync, or 14 00:01:05,440 --> 00:01:10,520 V-Sync, which would lock your graphics card's frame rate to your monitor's refresh rate. 15 00:01:10,520 --> 00:01:16,720 However, if your GPU's frame rate falls below your monitor's refresh rate, vertical 16 00:01:16,720 --> 00:01:22,720 sync can cause stuttering, as the GPU isn't finished rendering the next frame yet. 17 00:01:22,720 --> 00:01:28,240 VRR adjusts what your monitor is doing instead, making it a very attractive solution. 18 00:01:28,240 --> 00:01:33,440 While it is still possible to get tearing if your frame rate exceeds your monitor's maximum 19 00:01:33,440 --> 00:01:39,200 refresh rate, this can typically be solved by setting an FPS cap in your game settings. 20 00:01:39,200 --> 00:01:43,960 But not all VRR is created equal, as there are several different kinds of VRR buying 21 00:01:43,960 --> 00:01:50,120 for your attention. There's Vesa Adaptive Sync, which is an open source flavor of VRR that works on a driver 22 00:01:50,120 --> 00:01:56,560 level. AMD has FreeSync, which is really just Adaptive Sync that AMD has tested and put their stamp 23 00:01:56,560 --> 00:02:03,120 of approval on. Then there's NVIDIA, who has a group of solutions under the G-Sync umbrella. 24 00:02:03,120 --> 00:02:08,200 G-Sync, on its own, is a proprietary solution consisting of extra NVIDIA hardware built 25 00:02:08,200 --> 00:02:11,640 into the monitor to handle VRR processing. 26 00:02:11,640 --> 00:02:17,680 The term G-Sync-compatible, on the other hand, refers to an Adaptive Sync screen without 27 00:02:17,680 --> 00:02:22,560 extra NVIDIA hardware on the display, but that was tested by an NVIDIA to confirm it 28 00:02:22,560 --> 00:02:30,040 works well, similar to AMD's FreeSync. At the top of the NVIDIA food chain is G-Sync Ultimate, which includes fancier monitors 29 00:02:30,040 --> 00:02:35,600 with better HDR support, along with that special NVIDIA hardware built in. 30 00:02:35,600 --> 00:02:39,160 Compatibility is better than it used to be in that newer G-Sync displays that have the 31 00:02:39,160 --> 00:02:44,400 extra hardware can now work with non-NVIDIA graphics cards, even though this wasn't always 32 00:02:44,400 --> 00:02:50,840 the case. And the various flavors of Adaptive Sync should work on most modern GPUs. 33 00:02:50,840 --> 00:02:56,640 And VRR is part of the HDMI 2.1 spec and works similarly to Adaptive Sync, which is more 34 00:02:56,640 --> 00:03:01,680 of a DisplayPort thing. VRR can be susceptible to motion blur or ghosting. 35 00:03:01,680 --> 00:03:05,760 Although this problem is not unique to VRR, the issue is that displays can have a harder 36 00:03:05,760 --> 00:03:09,480 time compensating for it when VRR is enabled. 37 00:03:09,480 --> 00:03:13,160 You see, pixels have what's called a transition time to change from one shade of 38 00:03:13,160 --> 00:03:19,160 gray to another. And even though we use color monitors, we're talking about shades of gray because the actual 39 00:03:19,160 --> 00:03:23,440 light usually passes through a color filter to create the final image that you see. 40 00:03:23,440 --> 00:03:27,360 Anyhow, pixels are driven a certain amount so that they'll transition in a way that 41 00:03:27,360 --> 00:03:32,480 looks correct. When your refresh rate is changing so often with VRR, you'll also have to change the 42 00:03:32,480 --> 00:03:36,440 amount that you drive the pixels. And this can be tricky. 43 00:03:36,440 --> 00:03:41,040 If you don't do it, or don't do it right, blurring or artifacting can occur. 44 00:03:41,040 --> 00:03:45,680 VRR displays compensate for this by driving pixels a different amount or over-driving 45 00:03:45,680 --> 00:03:52,360 them depending on refresh rate. Determining the correct amount of overdrive requires extra processing and larger lookup 46 00:03:52,360 --> 00:03:56,520 tables which store the correct values the display should be using. 47 00:03:56,520 --> 00:04:02,360 Which brings us back to G-Sync. Monitors with G-Sync hardware inside tend to do a better job with this extra processing 48 00:04:02,360 --> 00:04:06,800 and give you an image with less motion blur. That's why the extra hardware. 49 00:04:06,800 --> 00:04:10,680 Now of course, we're not endorsing NVIDIA or telling you to go out and spend extra 50 00:04:10,680 --> 00:04:16,800 money on a G-Sync monitor. If you care more about preventing screen tearing and ghosting blur isn't something you typically 51 00:04:16,800 --> 00:04:20,680 notice, you might be completely happy with an adaptive sync monitor that'll cost you 52 00:04:20,680 --> 00:04:24,200 less money. Now if you'll excuse me, I gotta tear out of here. 53 00:04:24,200 --> 00:04:28,200 So thanks for watching guys, if you liked this video, you might also like our video 54 00:04:28,200 --> 00:04:32,120 on pixel cleaning. How does your OLED not burn in? 55 00:04:32,120 --> 00:04:34,620 What does that setting do? What is it? Check it out.