Can someone explain to me why high DPI is important in ULMB?

Ask about motion blur reduction in gaming monitors. Includes ULMB (Ultra Low Motion Blur), NVIDIA LightBoost, ASUS ELMB, BenQ/Zowie DyAc, Turbo240, ToastyX Strobelight, etc.
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GFresha
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Can someone explain to me why high DPI is important in ULMB?

Post by GFresha » 14 Jul 2019, 23:37

1) Why is it recommended to use high DPI and lower in game sens especially when using ULMB?

2) Why don't I see this same thing recommended for things like gsync, no sync, etc... Why is it more important in ULMB compared to other sync methods?

3) My software has 12000 DPI as max, should I go for 50% of that or lower? How much is "increase DPI"? I am using 800 right now and prob can go up to as high as 2000 or so but highly doubt I can get to 6000 DPI lol, is 2000 DPI good enough for ULMB?

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Re: Can someone explain to me why high DPI is important in U

Post by RealNC » 15 Jul 2019, 04:56

GFresha wrote:1) Why is it recommended to use high DPI and lower in game sens especially when using ULMB?
It's only important if your sens value causes pixel skipping. If it doesn't, then you don't need to do that. See:

https://www.youtube.com/watch?v=8XNUp70mDlQ

The reason it's especially important to not have pixel skips in ULMB is that that these skips can look stuttery. Normally, they look fine due to LCD blur. But ULMB lowers blur, so they can become visible.
2) Why don't I see this same thing recommended for things like gsync, no sync, etc... Why is it more important in ULMB compared to other sync methods?
Because with lower motion blur, you can see more stutters.
3) My software has 12000 DPI as max, should I go for 50% of that or lower? How much is "increase DPI"? I am using 800 right now and prob can go up to as high as 2000 or so but highly doubt I can get to 6000 DPI lol, is 2000 DPI good enough for ULMB?
Usually you use 400dpi, 800dpi or 1200dpi. 12000dpi is not useful for anything. Even half of that (6000dpi) is useless. Note that these extremely high DPI stats on mice are just marketing. They are completely useless in 99% of situations.

The only case they they are useful is when you play a game that switches you to a very low sensitivity in certain situations. Like a game where you can mount a turret, and moving the turret is a very slow and sluggish process that requires you to swipe the mouse like a madman to move the turret. In cases like this, having a button on the mouse that toggle DPI between normal (like 800) and a high value (like 6000) makes controlling the turrets easier.
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GFresha
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Re: Can someone explain to me why high DPI is important in U

Post by GFresha » 15 Jul 2019, 13:20

Perfect! Last thing

should I check or uncheck "disable full screen optimizations" ?

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Re: Can someone explain to me why high DPI is important in U

Post by RealNC » 15 Jul 2019, 13:41

GFresha wrote:Perfect! Last thing

should I check or uncheck "disable full screen optimizations" ?
I prefer leaving it on because for supported games it makes alt+tab just as easy as when playing in windowed mode, and it doesn't seem to introduce any input lag whatsoever. It doesn't work for all games though. But for games where it doesn't work, it just doesn't do anything, so it has no negative impact.

But I've seen reports where on some systems, FSO can result in forced vsync and DWM latency. Never had that problem myself, but it's worth verifying whether or not FSO results in forced vsync due to DWM compositing for you.
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Re: Can someone explain to me why high DPI is important in U

Post by Chief Blur Buster » 15 Jul 2019, 17:04

GFresha wrote:1) Why is it recommended to use high DPI and lower in game sens especially when using ULMB?
2) Why don't I see this same thing recommended for things like gsync, no sync, etc... Why is it more important in ULMB compared to other sync methods?
3) My software has 12000 DPI as max, should I go for 50% of that or lower? How much is "increase DPI"? I am using 800 right now and prob can go up to as high as 2000 or so but highly doubt I can get to 6000 DPI lol, is 2000 DPI good enough for ULMB?
Lack of motion blur = easier to see tiny microstutters.

Especially when you're turning slowly left/right, it moves really rough at 400dpi. The ULMB jitters.
You fix that by raising the DPI quite a bit, and reducing in-game sensitivity. Now slow mouseturns are smooth, much easier to track moderate-speed moving objects during ULMB. Your slow mouse tracking speed is effectively the same, but is a lot less jittery.

Try slowturning at about 960pps or so -- basically turn in a way that objects scroll horizontally past the screen in about 2 seconds. This will mean your mouse will slide very slowly.

Try this at 400dpi + high sensitivity, then try this again at 1600dpi + reduced sensitivity. You will notice that the latter is MUCH better for slow-speed tracking and medium-speed tracking. Fast tracking will not be affected nearly as much. You just need a mouse that will stay reliable with fast tracking at your high DPI. In the past, many mice did not do this reliably, but most gaming mice will keep tracking at your fastest movement speeds even at 1600dpi and beyond.

It can help GSYNC and VSYNC OFF to an extent but ULMB just particularly benefits a lot more because ULMB amplifies visibility of microstutters (no blur to hide tiny microstutters).

As a result, the use of high-DPI combined with low in-game sensitivity, can make playfeel of ULMB better. Getting that "TestUFO smooth zero blur effect" supersmooth slowturns in video games requires very accurate ultrahigh DPI.
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