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    Vsync and the PS3.

    As all of you hardcore PC UT'ers allready know...Vsync causes mouse lag...and for those that will be using a m/k combination to play on the PS3...I was wondering if you gave this much thought at all.I own a PS3 and also a gimped PC that will run UT3(Barely)...To me there's nothing more annoying than mouse lag....and without the option to turn off Vsync on the PS3 there will be an obvious disadvantage...I wish Epic would give us an idea of the kind of mouse behavior they have expierinced thus far on the PS3...Food for Thought-G-day

    #2
    Originally posted by Mental View Post
    As all of you hardcore PC UT'ers allready know...Vsync causes mouse lag...
    I am apparently not hardcore. I had to remind myself what vsync was. I mean, I knew it Vertical Synchronization and all, but I couldn't remember what was being synchronized vertically.

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      #3
      I don't have mouse lag and I use Vsync. There might be a way of alleviating that problem with settings like triple buffering or trilinear filtering. Reason I bring that up is because I have vsync enabled as well as those three. Perhaps that helps.

      Comment


        #4
        well.. it's not "lag", it's just that when the vsync is enabled, and you're under 125hz/fps.. your mouse will feel "jerky".. like some sort of smoothing.. really annoying.. but hey.. the PS3 will be on a LCD anyway.. so that's jerky either way.. disabling vsync wont help

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          #5
          Forget it, mouse feel on the PS3 via a TV is going to be horrid. You can compensate by using a high sensitivity. Normal players (and Epic designers) don't notice this difference apparently.

          Hell, I get tons of mouse lag simply playing at 1024x768 with an 85Hz refresh, I need 100Hz to make it feel responsive. A TV is what? 60Hz? :ugh:

          Comment


            #6
            Originally posted by doped View Post
            well.. it's not "lag", it's just that when the vsync is enabled, and you're under 125hz/fps.. your mouse will feel "jerky".. like some sort of smoothing.. really annoying.. but hey.. the PS3 will be on a LCD anyway.. so that's jerky either way.. disabling vsync wont help
            FYI the reason why it's called mouse lag is because on systems where this is a problem, you move your mouse quickly and the screen does not move at the same time. It follows belatedly and you can feel that disconnect between what your mouse is doing and the latency between what happens on the screen. It doesn't matter if the screen is an LCD or CRT, or if the refresh rate of the screen is 60Hz or 100Hz. That's just how frequently the updates are to the screen. Not whether or not what's happening on the screen is in sync with what your mouse is doing.

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              #7
              Ok guys,

              Say for example that you're running your mouse on USB at 125hz (default polling rate for USB ports) and you have a 60hz LCD monitor (Standard frequency these days) with a 16ms response time (also relatively standard). Also, your computer has just polled the USB port and your monitor has just rendered a frame. Immediately afterwards you move the mouse. It's going to take 8ms before that input is received during the next USB polling cycle (1 second / 125 pollings per second = 8ms per polling). It's also going to take 32.7ms before your monitor displays the next frame (1 second / 60 frames per second + 16ms response time = 32.7ms per frame). Adding the mouse time to this number brings us to a 40.7ms latency between input and visual response. (Ignoring the time it takes the electrical signals to transfer between hardware components since it's more or less negligible) Of course this is a worst case scenario and you might also have given the input right before the polling cycles and monitor refresh in which case you'd only be looking at the 16ms response time of the monitor. The response times vary evenly between these two numbers so on average you're looking at a 28.4ms total latency. (I'll let you do the math on your own at this point since most people won't read this far anyway and adding more numbers would only make that worse) With Vsync off the only variable frequency is the USB polling which brings you down to a 20ms average response time.

              In the above scenario you can see that Vsync will add, on average around 8.4ms of display lag. Some would argue that this won't affect your gameplay, and for the vast majority of people it won't. However, contrary to what the movie industry will have you believe air-force tests have shown that the most capable humans can detect events that occur in less than 1/200th of a second. This brings us to a 5ms meaningful response window, which makes 28.4ms look downright sluggish. Now, if you run a CRT, overclock your USB ports to 1000hz, and disable vsync, you'll be looking at only a .5ms average response time, which absolutely blows that out of the water. To be honest, I don't think any humans out there are actually capable of taking advantage of such a setup, which is why I'm comfortable "merely" leaving my USB ports at stock frequency and running a 2ms LCD, which brings me to a 6ms average response, which is close enough to 5ms for me (I doubt my eyes are as fast as the guys in the air-force test anyway).

              Now back in the real world you can still have fun regardless of the settings you use. Heck, you could even use a wireless mouse and get your response time up over 100ms (1/10th of a second) and if you're drunk enough you might not even notice! However, for the competitive scene these things do make a difference and I've just given you the math to prove it. Bringing mice and keyboards to consoles is a great first step, but not having access to USB polling rates and Vsync controls are just a few of several reasons why consoles are still inferior to PCs in a competitive enviornment.

              Comment


                #8
                Originally posted by nthexwn View Post
                ~snip~
                Mod this up for being informative !

                Comment


                  #9
                  Very nice!

                  I know in my experience, with the tweaks I normally do to UT2k4 I don't notice any lag when playing UT or UT2. But I've seen some bad stock settings with Vsync enabled on slow PC's and it's disturbingly noticable.

                  Comment


                    #10
                    Originally posted by nthexwn View Post
                    Ok guys,

                    Say for example that you're running your mouse on USB at 125hz (default polling rate for USB ports) and you have a 60hz LCD monitor (Standard frequency these days) with a 16ms response time (also relatively standard). Also, your computer has just polled the USB port and your monitor has just rendered a frame. Immediately afterwards you move the mouse. It's going to take 8ms before that input is received during the next USB polling cycle (1 second / 125 pollings per second = 8ms per polling). It's also going to take 32.7ms before your monitor displays the next frame (1 second / 60 frames per second + 16ms response time = 32.7ms per frame). Adding the mouse time to this number brings us to a 40.7ms latency between input and visual response. (Ignoring the time it takes the electrical signals to transfer between hardware components since it's more or less negligible) Of course this is a worst case scenario and you might also have given the input right before the polling cycles and monitor refresh in which case you'd only be looking at the 16ms response time of the monitor. The response times vary evenly between these two numbers so on average you're looking at a 28.4ms total latency. (I'll let you do the math on your own at this point since most people won't read this far anyway and adding more numbers would only make that worse) With Vsync off the only variable frequency is the USB polling which brings you down to a 20ms average response time.

                    In the above scenario you can see that Vsync will add, on average around 8.4ms of display lag. Some would argue that this won't affect your gameplay, and for the vast majority of people it won't. However, contrary to what the movie industry will have you believe air-force tests have shown that the most capable humans can detect events that occur in less than 1/200th of a second. This brings us to a 5ms meaningful response window, which makes 28.4ms look downright sluggish. Now, if you run a CRT, overclock your USB ports to 1000hz, and disable vsync, you'll be looking at only a .5ms average response time, which absolutely blows that out of the water. To be honest, I don't think any humans out there are actually capable of taking advantage of such a setup, which is why I'm comfortable "merely" leaving my USB ports at stock frequency and running a 2ms LCD, which brings me to a 6ms average response, which is close enough to 5ms for me (I doubt my eyes are as fast as the guys in the air-force test anyway).

                    Now back in the real world you can still have fun regardless of the settings you use. Heck, you could even use a wireless mouse and get your response time up over 100ms (1/10th of a second) and if you're drunk enough you might not even notice! However, for the competitive scene these things do make a difference and I've just given you the math to prove it. Bringing mice and keyboards to consoles is a great first step, but not having access to USB polling rates and Vsync controls are just a few of several reasons why consoles are still inferior to PCs in a competitive enviornment.
                    Thank you for that breakdown man....i wouldnt have hit that nail quite as squarely as you did

                    Comment


                      #11
                      I'm sorry, but a 2ms response time LCD has nothing to do with the refresh rate of LCDs, which 98% of LCDs run at 60hz, though there are some more expensive LCDs that run at 120hz.

                      I would still use CRTs, but I now get headaches from them, so I'm just with LCDs, and hoping to find a well-priced 120hz LCD soon.

                      Comment


                        #12
                        Originally posted by Spoudazo View Post
                        I'm sorry, but a 2ms response time LCD has nothing to do with the refresh rate of LCDs, which 98% of LCDs run at 60hz, though there are some more expensive LCDs that run at 120hz.

                        I would still use CRTs, but I now get headaches from them, so I'm just with LCDs, and hoping to find a well-priced 120hz LCD soon.
                        You're right, it doesn't affect the refresh rate. What it does affect is the overall display latency, from the time you move your mouse, to the time the camera position has changed on screen. There are several components to this latency in addition to having vsync enabled and I decided to include all the major ones in order to give a clearer and more complete understanding since there are a lot of misconceptions about this stuff.

                        A 120hz LCD would be nice though, and would have a much lower effect on display latency with vsync enabled than the 60hz LCDs do.

                        Comment


                          #13
                          Now all we need is for you to buy us both one.

                          Comment


                            #14
                            Originally posted by Spoudazo View Post
                            Now all we need is for you to buy us both one.
                            Judging by those system specs in your sig I think we know who's doing the buying! ;-p

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