Originally Posted by finaljason823
That's interesting, I wasn't aware of that. Which would be more favorable for gaming if you had to choose? My guess is G-Sync, but I'm not as familiar with ULMB.
The recommendation is:
- ULMB => games you play competitively.
- G-sync => games you play casually and you want to push to the max in terms of graphical settings for the wow effect.
ULMB stands for Ultra Low Motion Blur. It's an official implementation of the lightboost hack. ( Lightboost hack info here: http://www.blurbusters.com/zero-motion-blur/lightboost-faq/
On modern sample and hold LCD, the motion blur perceived (when tracking a moving object /panning the camera in an FPS/scrolling in an RTS/ etc) can be calculated easily.Image persistence (in milliseconds) = Motion blurring (in milliseconds)
(image persistence means the amount of time a static image is displayed)
60Hz without ULMB => image persistence = 16.7ms => 16.7ms of motion blur
120Hz without ULMB => image persistence = 8.3ms => 8.3ms of motion blur
144Hz without ULMB => image persistence = 6.9ms => 6.9ms of motion blur
Another interesting and simple calculation can be done to determine the length of the motion blurring trail.When tracking a moving object at 1000 pixels per second, the lengths of the motion blur (in pixels) = the image persistence (in milliseconds)
60Hz without ULMB => image persistence = 16.7ms => 16.7 pixels of motion blur when moving at 1000 pixels/s
120Hz without ULMB => image persistence = 8.3ms => 8.3 pixels of motion blur when moving at 1000 pixels/s
144Hz without ULMB => image persistence = 6.9ms => 6.9 pixels of motion blur when moving at 1000 pixels/s
You can see how hitting higher refresh rates and frame rates helps to reduce the amount of motion blur.
But the true magic happens when you use strobbed backlights. When a display is strobbing the images, the persistence will only be equal to the amount of time the static image is flashed on the display.
In the case of the ULMB mode which is included in G-sync monitors (such as the Asus rog swift and the Benq G-series) the image persistence is 2 milliseconds.
If you remember the formula, Image persistence (in milliseconds) = Motion blurring (in milliseconds)
85Hz with ULMB => image persistence = 2ms => 2ms of motion blur => 2 pixels of motion blur when moving at 1000 pixels/s
100Hz with ULMB => image persistence = 2ms => 2ms of motion blur => 2 pixels of motion blur when moving at 1000 pixels/s
120Hz with ULMB => image persistence = 2ms => 2ms of motion blur => 2 pixels of motion blur when moving at 1000 pixels/s
This is quite the improvement in motion quality.
It should be noted that for an optimal experience with ULMB, it's highly recommended to have:refresh rate = frame rate
If the frame rate is not matching the refresh rate, you will notice stuttering. (stuttering is very easy to notice in ULMB because it isn't 'hidden' by the motion blur)
And at low frame rate you'll start seeing one or several duplicates of the moving object you are tracking with your eyes.
60fps @ 120Hz with ULMB => You see two objects (Like if a ghost was following the object)
40fps @ 120Hz with ULMB => You see three objects
Ok. At this point, you will probably tell me:
"Well that's fine, I can set ULMB at 85Hz to play that demanding game that I manage to run at 85fps but I can't get to run at 100fps or 120fps."
And that would be a valid point.
But it must be noted that by its nature, ULMB makes the screen flicker.
Flickering becomes visible at refresh rates below the:
"Flicker fusion threshold
(The Flicker fusion threshold means the threshold at which you stop noticing the flickering.)
Every individual has his own sensibility to flickering and therefore his own flicker fusion threshold.
It is possible that you would be fine with only 85Hz, but it's also possible that you would not be fine below 100Hz. Or you might need 120Hz to stop noticing the flickering. That's something you'll need to fiddle with.
In case 85Hz and 100Hz with ULMB gives you too much eyestrain,
the only optimal option you will be left out with for competitive gaming would be: outputting 120fps @120Hz with ULMB
Hopes that clears things out a bit for the ULMB part.
Now for G-Sync, what it does is synchronize the refresh rate to the frame rate (as long as it's between 30fps and 144fps)
So G-Sync should feel like what a good stable V-sync feel like(no stutter, no tearing).
The advantage of g-sync over v-sync is that it doesn't need stable frame rates to produce that effect. And if the frame rate is below 144fps, it won't add input lag like v-sync would.
Therefore g-sync is nice for playing a casual single player campaign at max graphical settings on a very demanding game.
I haven't got a g-sync monitor to test (yet) so I can't give you my subjective personal opinion on exactly how it feels. It's a very interesting and welcome feature. And is one of the reason I decided to go with an NVIDIA graphic card for my upcoming build.
But you must be aware that:
-in no way it's a substitute to getting high frame rate.
-it can't be used in ULMB low persistence mode.
For more reading about G-Sync:
(overview of the advantages of g-sync)
(input lag measurement with g-sync)
If you need more help about displays, g-sync, input lag, motion blurring, ...
I highly recommend posting in the blurbuster forum: http://forums.blurbusters.com/