All this back and forth arguing when really everyone is saying about the same thing only in different words is exhausting. Hahaha. Really all that matters to sim racers is the total lag from the time we move the wheel to the time we see it. I think KeiKei's original post was most useful as it points out the things we can do with software to minimize lag without throwing more money at the problem. Sure we can shop for a monitor with the lowest advertised response time but that doesn't really mean the advertised numbers are even accurate.
Novis, like I said, sure maybe refresh rate affects input lag, but it is so tiny, tiny, that it is almost not even worth mentioning, and definetely not arguing over. There are 60/120 hz monitors/tvs that have 3ms total measured input lag, ones with 8, 12, 15, 18, 25, 40, 60, 80, even over 100 ms. They are all the EXACT same refresh rate (60 or 120 hz), but have HUGE differences in total measured input lag, that alone should obviously tell you that refresh rate barely makes a difference to input lag, and that it is something else that is causing 99% of it. Some Tvs even have a game mode, specifically for reducing input lag, sometimes this setting can really make a good difference on input lag levels, however the refresh rate doesn't change, the difference is from less post-processing, like gearjammer explained.
Yeah exactly! There really is no point arguing about the basically same thing but with slightly different terms. And there's no measured data shown about which part of the process takes the longest and therefore no point arguing what is more important over other. BTW if some part's input lag is lowered then some other part might become dominant so it's all relative. Don't mean I'm not interested to see input lags of individual parts but just like Noel said; in the end all that matters is the total lag from controller to eyes. Period? Please?
Finally did input lag measurements with KeiKei's method (except i used a second computer for capturing). Some interesting findings: * windowed mode (set in rfactor2 Launcher -> configure sim) adds 45ms to input lag * Stereoscopic 3D didn't add input lag (using 3D Vision, interlaced, adaptive vsync, 2D and 3D were both at 60Hz FPS) I knew that my 55" 3DTV has alot lag, and i put a lot of effort to bring it down to 30ms before, but now found out that it have to be 50ms again comparing my values to KeiKei's. Again have to optimize the TV's input lag. If someone doesn't know: * Don't use a TV for simracing except you really know the input lag! So first big improvements here: -45ms cause of windowed mode, and saved some ms by using no sync instead of adaptive vsync.
I would generally never recommend using windowed mode for rf1/2, I also remember it has worse fps than full screen and to think it also adds input lag, meh. I don't see reason to do it anyway because I never had problems with alt tabing, except when I used 3rd party dlls for HDR which make the game look like cartoon anyway, with such alt tabing causes crash.
The reason that windowed mode is so terrible is because not only does the system have to maintain all the resources from the game, but also from Windows. When running an application in full screen, Windows can release some resources normally used to display stuff in Windows. This is also why some applications will crash when trying to alt-tab out of them.
Sorry forgot to answer this. #4 and #10 are with high graphic settings and game engine provided about 60-70 FPS. #4 was with vsync off and #10 was with vsync on. Difference is huge when max pre-rendered frames is not used. #13 is with max pre-rendered frames = 1 and lag is considerably lower. Difference seems to be 16 ms but accuracy with 187 FPS camera isn't very good. If first value shows 4 ms too low and second value 4 ms too high then there's 8 ms error between those two hence real difference would be 8 ms. Unfortunately couldn't see tearing lines because camera resolution is so low when FPS is set high (and also everything else was stationary except steering wheel which was mainly behind the real wheel). Max pre-rendered frames were always 1 when used and other cases were set to control by the application (rF2).
Another possibility is that KeiKei's G27 does have less lag than my Fantatec CSRE. Is that possible? Since my friend's G25 is still in my flat, i will compare these two wheels tomorrow regarding lag.
I'm guessing there's no difference between those two but very interested to see the results of your test.
Wow, very interesting about windowed mode adding 45ms. I have never really noticed input lag and I use windowed mode onto my 2nd monitor which is a 32" Samsung TV!! Btw I use nearly highest graphics settings and get 70-100fps.
Ok, thank you for the report. I wish I had a cam of my own because it would be interesting to test and see my own lag. Under 30 ms is a fantastic result with current technology. The possibility is that it can be depending on drivers. I think I remember that Fanatec updated the polling frequency when the T500 was released as it used a higher one. The difference shouln'd be more than a few ms at most.
I found one input lag measurement of my Asus VE278Q: REVIEW: Asus VE278Q Part 14 Here's what they said (translated from Germany by Google): I guess this monitor is using overdrive technology which adds 18 ms of lag. Think I'll have to make new tests with different Trace Free settings and see if there are differences.
Hmm, if my total input lag was 26 ms and my current monitor was 19 ms then there are 7 ms created elsewhere. Since physics and controller operate at 400 Hz then those took 2,5 ms each so there is only 2 ms unknown. Could it be the case? Or maybe my monitor doesn't have that much lag after all and there's more lag elsewhere.
Dont forget the 200 ms human reaction time + the amount of time to late the ffb gives backend information.
Well, as this discussion all started when Keikei raised the point if a 120 Hz refresh rate would make a difference in lag and then someone answer, no it wouldn't. I thought it would be the correct thing and show that indeed the refresh rate has a major role in the lag. In contrary, most parts that cause lag are very well documented and known. From the hardware point almost every factor can be calculated or measured. The part that differs is game depended, the time from where the game samples the input device and output that change to the screen. The point is that it is very hard to measure total lag. You need a high speed camera to record the user input and the image on the screen. Just like the way you did. That is what makes all these experiments so interesting. Sorry but I simply don't get it. In several threads here on the forum you go on and say that your new 3 ms monitor makes such a huge difference on your game play, and your old 20 ms monitor sucked. And then you refuse to accept that the refresh rate makes up about half of the lag on a 60 Hz monitor and will give you 32 ms lag in parts of the screen. You seem to know a lot about input lag why don't you read up a little bit on how the display creates the image on screen. Understanding where the lag comes from is the only way to reduce it. The monitor input lag today is a minor factor in the total lag caused by the display. Changing to a 120 Hz monitor will simply remove another 8 ms of lag. So, when you go shopping monitors looking at the refresh rate is as important as looking at input lag.
Yeah important factors too but don't affect the total lag between controller and eyes - which I'm currently interested on.
Hmm, I think I backpaddle on what I wrote here before. Hopefully nobody saw it! Keikey, You should have a variation of the measured lag in the playback of the cam of 16 ms. In the very best case of that measured lag you will have 0 ms of refresh lag, in the very worst case you will have a full 16 ms of refresh lag.
There are many, many 60hz monitors that have 8 or less ms of input lag, so according to your theory if going to 120hz magically gets rid of 8 ms of input lag then why arent there many (or any at all) 120hz monitors with 0 input lag??!!!! 120hz only updates the image quicker, 8ms of time from displaying one frame to another, but you are still behind the software due to post processing and other overhead that all Lcds and plasmas do!! Jesus Christ man try researching this, and stop going by your stupid theories, you're not a genius scientist, try going on the internet and research the subject called "monitor input lag"! You are the most ignorant and stubborn person i probably have ever spoken with on a forum.
