Gadgetory

especially old forums seem to be littered with misinformation in regards to topics like the one in this video for example this GameSpot threads Opie asking whether he can see 100 FPS on a 75 Hertz display receive responses like it's true and you can't see 100 FPS anyways here's another LCDs do not have refresh rates they have response times but what really happens when more frames and the monitor can process are sent from the GPU and what is screen tearing on a technical level and how does vsync solve this issue welcome to probably a very long episode of minute science every point zero one six seven seconds or thereabout sir point zero zero eight three seconds or point zero zero four two seconds your monitor likely refreshes these are refresh rates adopting the unit Hertz the SI unit of frequency denoted as the multiplicative inverse of seconds so when a monitor has a 60 Hertz refresh rate it switches images or stills 60 times per second frames are usually drawn from top to bottom at speeds our eyes are incapable of discerning and are left on screen for a duration of 1 / the refresh rate itself but what happens when you send more than the number of frames a screen can process what happens when a 60 Hertz monitor let's say receives 100 frames per second on average from a graphics card and no I'm not just talking about screen tearing that's the obvious answer I want to know what happens on a technical level inside the monitor well if we assume a constant 60 Hertz refresh rate like with this monitor here and a constant 90 FPS draw from the graphics card then we're at a roughly 121.5 deficit on the GPU side meaning half of every other frame won't be processed by the monitor at least on paper now in the real world monitors only call frames when they need them so the very first frame at these ratios with a perfectly fine once the simulation starts one frame sent and one frame displayed but since the monitor isn't refreshing fast enough the next image displayed will consist of only half of the next full frame you can look at this mathematically by separating each rate in additive steps using our ratio one plus one plus one for the monitor and one point five plus one point five plus one point five for the GPU again constant framerate on the second refresh from the monitor when it's step is to the graphics card is already halfway through its second frame so the monitor compensates by displaying half of the second frame and the first half of the third in this scenario since the other half of the data from the previous frame was overridden by the graphics cards higher pace if it didn't override the previous frame the video would become delayed increasing input lag to the degree that this was allowed to continue at step three the graphics card will be sending its fourth frame because they're in sync again and then the cycle repeats it goes out of sync by a half step and then it's back in sync and it keeps alternating now the yield what we get from that is what we call screen tearing and it literally looks like the screen is being torn down the middle but I should clarify where it's torn depends largely on the refresh to FPS ratio at that time in this particular example everything's on a 1 to 1.5 ratio so the monitor would ideally split every other frame perfectly across the center and something else to note screen tere occurs horizontally because frames are usually drawn in a top-to-bottom fashion now this is where vsync comes in when enable that forces the graphics card to literally synchronize its frame rate the frames that it's outputting to the monitor with the calls from the monitor it'll also typically reduce hardware utilization but this isn't foolproof so you might notice a temperature drop or maybe the fans spool down just a little bit but this is more or less a byproduct of using vsync in the event that you would normally have a much higher frame rate being thrown to the monitor now there may be visual benefits to running at a frame rate higher than your refresh rate even though technically speaking you can't see those extra frames so many professional FPS gamers in particular keep vsync off because they swear by the decreased input lag and faster interpolations required when aiming here's what an overwatch player had to say in any case I disabled the vsync recently and wow what a difference I can aim now I always had this issue where I'd be tracking a target like a running soldier and my crosshair would always lag a tiny bit behind where they were I always thought this was just some practice or mental block issue where I hadn't trained my hand-eye coordination to compensate or something now it doesn't happen any or I have a couple of friends who have reported the same feeling it's such a tiny one sixtieth of a second delay it's hard for your brain to realize it's not the one making the mistake my wife swears by vsync off despite the occasional screen tearing and I can kind of see why but at higher refresh rates these advantages become less apparent in principle so at 60 Hertz the maximum delay incurred with vsync on would approach one sixtieth of a second right in time for the next frame to be in sync with the refresh rate but at 240 Hertz the max delay with vsync is 1 to 40th of a second which could make a visual difference to many though the effectiveness of vsync at these rates anyway is probably pretty moved so in summary extra frames are overridden or split in accordance with the refresh rate in question but with vsync on the graphics card draws as many frames as the monitor calls so no splitting or screen tearing is necessary maybe only a slight delay that I don't expect too many people would notice except maybe those who play and on a professionally or really intense first-person shooters I don't know what you think about this topic in the comments below if you play with vsync on or off we haven't really touched on freesync or g-sync which are proprietary technologies from AMD and both more proprietary for nvidia on the g-sync side but those technologies are for a separate video I just wanted to highlight vsync here because almost anybody has access to that as long as you're playing a relatively modern game you can turn on the vsync function or the you know 1x 2x or 3x buffer which would basically store those frames in your graphics cards memory kind of a similar process to vsync just call it something different on paper so if you like the video you can let me know give someone a thumbs up I appreciate it thumbs down for a V oppositely to subscribe button if you haven't already in stay tuned for more content like this this is science studio thanks for learning with us you