Yes I had some fluctuation for example on 178 FPS thing there was something like 20 ... 32 ms but didn't write those down at that point. Made lots of measurements from different points so could determine the average value. When there was greater fluctuation in later test then I wrote those down. It isn't very easy because best accuracy with 187 FPS camera is only about 5 ms.
I think it's not 8 -> 0 ms but 16 -> 8 ms what Novis is meaning. And there is still the base input lag on both monitors for example 3,3 ms which must be added to 16 or 8 ms (60 and 120 Hz monitors). The 8 ms is reduced elsewhere and has nothing to do with pure monitor input lag but I think it's the "refresh rate input lag" which is only related to the refresh rate. Novis is talking about the lag which is caused because the way how image is drawn on screen. It's always there even the monitor input lag would be 0 ms. Just like the monitor input lag is always there even if refresh rate input lag would be 0. Based on the conversation between you two I'm pretty sure he thinks the same about you too. But seriously guys you should stop arguing about this issue. They are two separate things and both cause independent lag. The one which creates more lag depends on circumstances. If current monitor has already low input lag say 6 ms then there's only 3 ms gained if switched to 3 ms monitor. If current monitor's refresh rate is 120 Hz then there is only 4 ms gained if switched to 240 Hz refresh rate monitor. It's all relative and depends what is one's starting point. By the way increasing refresh rate is exponential so by doubling refresh rate the input lag (=not the monitor input lag but refresh rate input lag) is reduced to half: 60 Hz: 16,7 ms 120 Hz: 8,3 ms 240 Hz: 4,1 ms 480 Hz: 2,1 ms 960 Hz: 1,0 ms
Yes you're right but the lowest wasn't of course 0 ms because my monitor has the base input lag of maybe 15 ms (=Spinelli's monitor input lag). If you add other input lags say 5 ms from physics engine, controller polling rate, etc. then you end up 20 ms of total input lag which was the lowest I saw. Then when the screen drawing process (=Novis' refresh rate input lag) was in the worst phase then total input lag would have been 15 ms + 5 ms + 16 ms = 36 ms. That's not very far from the highest input lag I saw for the 178 FPS.
Now I'm a bit disapointed. I thought you were the expert on definitions of display terms. Refresh lag and input lag has nothing to to with each other. Jesus, that is what both I and Gearjammer have been saying all the time. Reducing refresh lag will not alter the input lag. It is just you that keep saying that. So no, it's not just my definition. Sorry I'm stubborn, but at least I am not stubbornly wrong. It's it not my theory, it's the way the graphics card transfer data to the screen. It is fundamental physics. Everyone that have been programming anything having to with graphics or has been involved in video hardware know about this. It's not me that have to do the research. I'm trying to teach you something like you did to me when you corrected my view on display input lag and response time. But you sure don't make it easy for me.
I want to clarify this bit further. Let's assume all those different monitors have 3 ms input lag. Let's also assume physics engine, controller polling rate, etc. add 5 ms input lag. Then total input lags with different monitors would be: 60 Hz: 5 + 3 + 16,7 = 24,7 ms 120 Hz: 5 + 3 + 8,3 = 16,3 ms 240 Hz: 5 + 3 + 4,1 = 12,1 ms 480 Hz: 5 + 3 + 2,1 = 10,1 ms 960 Hz: 5 + 3 + 1,0 = 9,0 ms
Exactly. As the update of the screen is a continuous process the refresh lag of an inividual pixel will vary over time when running without vsync. There is no constant refresh lag. I say it again, on an individual pixel it will vary from frame to frame. It can be anything between 0 ms to 33.6 ms with vsync and 0 ms to 16.6 ms (plus the frame rate factor) without vsync depending on what pixel you are looking on in a frame. When discussing refresh lag you take the average lag of all pixels in a frame, and that time is the average of the two pixel extreems. Edit: As KeiKei updated his post I do the same. A 60 Hz display will have 0 ms refresh lag at some pixels, but there will be many more pixels with higher lag. The difference with a 120 Hz display is that the maximum pixel lag will be half of that on a 60 Mz display.
This has nothin to do with the graphics card, this is to do with what the monitor/tv does after it has received the information from the graphics card but before it displays it on screen. The monitor/tv does lots or little (depending on the monitor/tv) post processing, interpolation, scaling, double buffering (not GPU buffering, but the monitor's/tv's own internal buffering), etc etc etc. Any 60 fps/60 hz monitor/tv with double buffering will always be at least a frame behind 1 frame=16ish ms. A monitor/tv with double buffering but at 120 fps/120 hz will also be behind 1 frame, but that frame is now only 8ish ms, so in monitors/tvs WITH INTERNAL DOUBLE BUFFERING you get half of the refresh lag when going from 60fps/60hz to 120fps/120hz. Then you still have to add that lag to all the lag from the post processing and such (post processing lag is where most lag comes from and has nothing to do with refresh rate, this happens before refresh). The thing is though, that is only relevant for monitors/tvs that do internal double buffering, go look up how many of our pc monitors actually use double buffering . If you don't understand double buffering of the monitor don't reply saying that I'm stubbornly wrong because you "think" this and you "think" that. Go actually read and research, THEN I'll be happy to listen to your facts. This was about monitor input lag, the overall input lag specific from a monitor, not just the "refresh lag", but the entire input lag from the monitor. The monitors post processing is what contributes to 95% of the input lag. Refresh lag regardless of 60hz or 120hz, on a monitor with no internal double buffering will barley make any difference to the overall input lag of the monitor, especially in relation to how big of an impact the post processing makes to the total monitor input lag.
I did tests with Logitech G25 and Fanatec CSRE -> exactly the same measured lag (tested using Sync off, Max pre-rendered frames = 1, 146 FPS)
We obviously have a communication problem here... Great! Exactly! The time required to transfer the frame data from the graphics card to the monitor is the refresh lag. The refresh time has nothing to do with input lag. This has been the whole point of my in this discussion. Do you get it now? I am very familiar about double buffering thank you. Double buffering is used to do deinterlacing, frame interpolation or any other kind of post frame processing. But as you say double buffering is part of the input lag. It has nothing to do with this discussion as it will only add to the input lag. Input lag isn't the total lag of a monitor. Input lag is only the part of the lag in the monitor from when it is given the signal data for one pixel to the time that pixel is showing a response to the new color data. The input lag of a monitor has nothing to do with the time it takes to update the whole frame, only a single pixel. If a monitor has 3 ms input lag doesn’t mean that it takes 3 ms to update the whole frame. It means that a single pixel has taken 3 ms to process and update on the display. At 60 Hz the whole frame will take 16.6 ms to redraw whatever the input lag. The input lag just is a number to describe the delay of the frame. Is that the main problem here? I've been trying to say that multiple times. The total lag of a monitor is the time to transmit frame data (refresh lag) plus input lag. Pixels are transferred continuous during the whole refresh time. Dare I point you to my post #42 again for how all this work? As you say the best LCD monitors have input lag in the region of a few ms. That is because they do close to no pixel processing. The main part of the lag comes from the time to light up the liquid crystal and have it react to the new color input and the pixel reaction time depends mainly on display technology. I say it again. The refresh lag is the average time it takes for the pixel data to be transferred to the monitor and has nothing to do with input lag. Input lag is how the monitor processes that data afterwards and makes the display change color of a single pixel. A 120 Hz monitor will make the data transfer time in half the time of a 60 Hz monitor and hence have lesser lag. It shouldn't be that hard to understand. Finally: Input lag does not include the refresh lag. The total lag of a monitor is refresh lag plus input lag. My main crusade here has been that the refresh rate will influence the monitor lag. Hopefully now as it should be perfectly clear to anybody that has been reading this thread and no longer be misinformed.
The refresh rate of a monitor without double buffering will have a very, vey, very tiny affect on the total input lag of a monitor relative to how much an affect the post-processing and such has an effect on the total input lag. This is proved by some of the amazingly low total input lag times that are being achieved by monitors that are "only" 60 hz. This is also proved by looking at charts of monitors with the least input lag, from various websites, and clearly seeing the 60hz monitors are littered on the charts with amazingly low input lag test results, and seeing 120hz monitors which are well further down the order. This is obviously not to say that 120hz monitors have more lag because they are further down the order, but rather, shows more evidence that amazingly low times of input lag are consistently achievable with 60hz monitors, therefore indicating that the refresh rate (60 vs 120hz) has very, very little effect on total monitor input lag. That's all I was trying to say, as I didn't like how you were seemingly (to me) misleading others into thinking that choosing a 120 hz monitor over a 60hz monitor would get rid of, or minimize their total monitor input lag, which isn't the case one bit if you look at all the test results of monitors with the best/lowest input lag which are full of 60hz TN panels at the very, very top places. So in the end, the test results from many different websites, many different reviews, clearly prove this. Despite our "technical stuff" arguing, in the end, the hard facts of years of test results clearly prove this, and that's all that matters. Actually really all that matters is that, in the end who cares, we love racing, we love racing sims, as long as you feel good about your monitor and "feel" than that's all that matters .
Thanks! It's good to have confirmation that at least between those two controllers there's no difference in lags.
Yeah if I had 3,3 ms 60 Hz monitor, average refresh rate lag of 11 ms with 179 FPS method, 2,5 ms from game engine and 2,5 ms from controller polling rate that would be 19,3 ms total input lag which I would consider extremely low! Also the 179 FPS method creates very little lag fluctuation so the total input lag would stay around 11...27 ms!
Well, you are wrong. I think you have zoomed in so hard on the term input lag without understanding the context it is used in. What you have read about input lag isn't the total lag of a monitor. Here is a tutorial on digital video from National: http://www.ni.com/white-paper/9492/en Take a read as it isn't that long and you shouldn't have to read more than about half of the page to understand the concept of display frames and pixel clock rate. Reread the section on Digital Video Sample Rates and Timing a few time as that is the important part. It could be useful to use your calculator and enter the numbers yourself to understand how the time of a frame adds up. To understand the transfer order of the pixels in an image take a look at analog PAL or NTSC timings they usually have images to show how the electron gun is moving or have a look here at How Stuff Work (http://electronics.howstuffworks.com/tv7.htm). The principle of pixel data tranfser in digital protocols is the same except that noninterlaced mode is mostly used by computers. It should probably be enough to understand that the image is sent with the upper lines first and the lower lines last. When you understand the concept of frame transfer you will also understand why tearing will happen when running without vsync.
I think Tim posted the polling rate a year ago on the T500. I'm a long way from being sure but think it was 500 Hz at that time. If so the lag from the steering wheel should vary anywhere between 0 and 4 ms. That short time would be hard to detect when there are other parts in the chain that have much more higher variation of lag.
Novis, how could you just straight up say I'm wrong lol you are hilarious, it's not about me being wrong or right, I am just telling you the results from great websites like prad.de and many others which have years of input lag tests. All these websites tests have a ton of 60hz monitors at the very top places for least amount of input lag. So I guess you are right and all the different review websites that do tests are wrong. Haha ok, my time is done here man, have a good day lol.
G25,G27 poll with 500Hz, Fanatec CSRE 500Hz (http://f-wheel.com/reviews/csr-elite-wheel-benchmarked) Thrustmaster after firmware update is 500Hz too. Ideally theres only 0-4ms lag and that is hard (if at all) measurable with this method. The reason why i compared the G25 and the CSRE is because im searching for another big lag source. 1st one was windowed mode with 45 ms. That got me down from 125ms to 80ms. (Sync off, Max pre-rendered frames = 1, 146 FPS). The wheel was one difference to KeiKei's system. 80ms is still to high. KeiKei's input lag is ~30ms at 150 FP. -> Im losing 50ms somewhere. I measured and optimized my TV to have only 16ms more lag than my HPLP2475w monitor (the new model which should have 4ms lag, and was my reference for the TV's input lag measurement). KeiKei's Asus VE278Q should have a delay time of 17.9 -> where do i lose the 50ms? I suspected nvidia clone mode ( or is it called TwinView?) but that didn't add lag. I am suspecting the TV again ... the search goes on ...
I have measured my setup with PSeye for lag too. I have G27 and use my TV Samsung L32B550. I get ~75ms lag in fullscreen mode. Have TV in game mode and everything. I may consider buying a monitor to minimize this lag.
Cool that running multiple monitors didn't add lag. Do I understand you correctly that you run rFactor cloned on both screens? Have you measured lag on both the TV and the monitor? Main factors I can think of right now that can add lag: - Have you changed pre-rendered frames in the nVidia drivers to 1? - Do you run native resolution on the TV?
Can't think of anything else. Hmm, one possibility could be if something isn't right with the captured video. I don't know how for example Avidemux is calculating the time but if the captured video is corrupted then it could be possible that you actually had lower lag than what Avidemux was showing. Personally verified the first captured video by advancing 1 second frame by frame based on the time at lower left corner of Avidemux and counted how many frames I had to advance. If everything is right then you should have counted 187 frames.
