Mouse 125Hz vs 500Hz vs 1000Hz visible when strobed or GSYNC

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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Re: Mouse 125Hz vs 500Hz vs 1000Hz visible when strobed or G

Post by Chief Blur Buster » 08 Jun 2014, 12:19

fenderjaguar wrote:I see. So it doesn't really matter if you're using 2.0 or 3.0?
Only if the mouse is USB 3.0

But I don't think it makes a difference because mice are still tantamount to USB 1.1 (not even 2.0) but that still can transmit over 10,000 USB packets per second (if the USB packets are small). The main issue is timing jitter, and that is likely more accurate on new USB ports than older USB ports.
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Re: Mouse 125Hz vs 500Hz vs 1000Hz visible when strobed or G

Post by Chief Blur Buster » 08 Jun 2014, 12:28

BTW, upon closer inspection, I even barely see microstutter during the "tiny text window drag test" during 1000Hz poll rate, when I adjust my monitor's persistence to 1.0ms or less (BENQ Z-Series). It's not visible on my ULMB though because ULMB has too much motion blur compared to 1.0ms persistence. It's very hard to see, but I also notice it's photographically visible. Here is an enlargement that shows my microsutter math is correct for 1000Hz, too:

Image

mouse pollrate = 1000 Hz
refresh rate = 120 Hz
(1000 MOD 120) = 40 microstutter per second
40 microstutters per second at 120Hz = 40/120 = 1 stutter every 3 cursor positions
Which is exactly what this photo shows.
Microstutter amplitude is extremely small, but visible in this photo.

Once we've got ultrabright low-persistence rolling-scan 240Hz OLED with 1.0ms persistence (or less), I think 2000Hz mice will actually be visually useful to some motion clarity nuts (like me). it goes to show, that there are still surprising side effects (e.g. stutters as a harmonic frequency side effect)

Oculus has the luxury of keeping its head tracking Hz perfectly in sync in refresh Hz, but mice makers do not have the luxury of synchronizing mouse Hz exactly with display Hz. It is possible with GSYNC though (e.g. 125Hz Quake Live on GSYNC monitors, where the game engine timing is driven by the mouse timing, and then consequently the monitor refresh timing from the game engine, potentially causing perfect display synchronization with mouse Hz).

During unsynchronized Hz situations (e.g. uncapped VSYNC OFF) you want a really high mouse pollrate to avoid the harmonic beat-frequency effects between dissimilar Hz. Especially when there's no motion blur to obscure microstutters, and we all know that LightBoost/strobing makes stutters more visible. So you really want to keep microstutters under control, when using sdtrobing. It really goes without saying, that if you're a LightBoost lover (i.e. you can really see the benefits), you really want to set your mouse to 1000Hz, not 500Hz.
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Re: Mouse 125Hz vs 500Hz vs 1000Hz visible when strobed or G

Post by RealNC » 08 Jun 2014, 13:08

fenderjaguar wrote:
RealNC wrote:Polling rate is independent from data transfer speed. 1000Hz in USB 2 works just the same as in USB 3. Polling rate is how many times per second you read something from USB, not how much data you read.
I see. So it doesn't really matter if you're using 2.0 or 3.0?

Only reason I ask, is I have some 3.0 ports, but I use windows 7. And whilst there are drivers that support it, I heard windows 7 doesn't support usb 3.0 properly or something, so I avoid using them.
As Chief said, Mice don't gain anything with USB 3.

Windows 7 indeed does not have built-in USB 3 support. But after you install the drivers for your USB controller, they work like a charm. I've been using USB 3 (for a fast USB 3 stick, 110MB/s write, 190MB/s read) for a long time without a single issue.

Note that when you have USB 3 drivers installed, and if you connect a USB 3 capable device to a USB 2 port, then Windows will tell you about it. It says something like "This device will perform much better if you connect it to a USB 3 port." So don't worry about it. If you happen to connect anything to a USB 2 port that would actually benefit from USB 3, Windows will tell you so.
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Re: Mouse 125Hz vs 500Hz vs 1000Hz visible when strobed or G

Post by Trip » 08 Jun 2014, 18:16

This might seem like a dumb suggestion but since these new monitors are mostly capable of 144hz. Why not just dial the frequency back to 125hz and you do not have any microstutters at all. It goes to show that these timing mismatches of all these different elements are really bothersome. I would wish everyone(game engine makers, monitor developers, usb standard) would just universally agree to use the same timing standards the only difference being a multiplication by a natural number.
We will probably not see a 250hz display next but a 240hz display :(.

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Re: Mouse 125Hz vs 500Hz vs 1000Hz visible when strobed or G

Post by flood » 08 Jun 2014, 19:21

honestly for 500hz mice, if microstutter is seriously a problem, you could just add 2ms of input lag and interpolate the mouse position using the previous two samples...

big deal since if you want motion clarity you'd be using double buffering and strobing, both of which add more than 2ms input lag

by the way, here's a nice picture of my 500hz g100s on a 144hz monitor. it's easy to notice that the gaps are not uniform when moving the cursor around, but when dragging things, its hard to notice due to persistence/motion blur.

http://i.imgur.com/b3alHfZ.jpg

500hz on 144hz is probably the most visible scenario because there's aliasing/gaps every other frame.

here's a picture of perfect motion (500hz on 100hz):
http://i.imgur.com/umwHgjy.jpg

anyway, concerning the thread title, these aliasing/temporal moire/microstutter/whatever effects are visible without strobing.

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Re: Mouse 125Hz vs 500Hz vs 1000Hz visible when strobed or G

Post by Chief Blur Buster » 08 Jun 2014, 21:07

flood wrote:honestly for 500hz mice, if microstutter is seriously a problem, you could just add 2ms of input lag and interpolate the mouse position using the previous two samples...
Yes, that's the mouse smoothing feature built into many games. The interpolation reduces the mouse microstutters a lot.
flood wrote:big deal since if you want motion clarity you'd be using double buffering and strobing, both of which add more than 2ms input lag
Although it is the most noticeable at perfectly synchronized framerate-refreshrate, it still can be seen during VSYNC OFF too.

Especially VSYNC OFF during strobing, and ultrahigh framerates (e.g. 300-500fps), like 700series/Titan in Source Engine games, can make microstutters extremely tiny even with strobing. The microstutter differences of 500Hz vs 1000Hz actually begins to become noticeable even with VSYNC OFF during strobing, when you're hitting the multiple-triple-digit framerates.

There are certain cases where you are willing to give up just a small bit of input lag by enabling strobing, in the certain situations (certain gameplay tactics in certain games) outweighs the lag tradeoff. But then you don't want to add anymore lag from any point in the chain. During future rolling scan OLED, there is no input lag from rolling-scans, so you can have lag-free "strobing" by impulsing in a rolling scan like a CRT. So you can achieve low persistence without lag by using the rolling scan technique. So, I want to see 2000Hz mice happen. At the very least, it will make 1000Hz sensors more accurate, at the least.
flood wrote:by the way, here's a nice picture of my 500hz g100s on a 144hz monitor. it's easy to notice that the gaps are not uniform when moving the cursor around, but when dragging things, its hard to notice due to persistence/motion blur.
Yes. You really need low persistence to easily see the 500Hz microstutters. Though, it is still visible even at 144Hz,
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Re: Mouse 125Hz vs 500Hz vs 1000Hz visible when strobed or G

Post by Chief Blur Buster » 08 Jun 2014, 21:12

Trip wrote:This might seem like a dumb suggestion but since these new monitors are mostly capable of 144hz. Why not just dial the frequency back to 125hz and you do not have any microstutters at all.
That works, if you can get the monitor Hz exactly the same as mouse Hz. In real life, the monitor might be 125.1Hz and the mouse might be 124.9Hz. This 0.2Hz difference is 1 stutter every 5 seconds. It could get closer than that though. Also, there will be a slowly slewing input lag effect right before each stutter, due to the drifting Hz difference. For a 125Hz mouse, for example -- you have mouse input lag slowly varying from 0ms through 8ms! Just right before the stutter, the input lag may be maximized/minimized (T+0/125sec or T+1/125sec), and right after the stutter, it becomes vice versa (minimized/maximized). A slowly-varying input lag is a Bad Thing.

So there must be perfect sync, if you wanted to lower the mouse Hz back to 125Hz, and then set the monitor to 125Hz. One of the devices need to be the master clock, and all other devices synchronizing to it. Few game engines synchronize their framerate to the mouse Hz (Quake Live was one of them, I believe). Ideally, mouse becomes the master Hz, for the minimum input lag. That's why it could work with game engines that synchronize to the mouse Hz, and then consequently monitors that synchronize to the game framerate (e.g. GSYNC). In this situation, you can have perfect sync (at least during 125fps mode rather than 250fps mode), by combining GSYNC + framerate synchronized to the mouse Hz, provided the mouse Hz is below the GSYNC's maximum Hz.

In real life, precision synchronization isn't going to happen, so we need 1000Hz (and, soon 2000Hz for low-persistence zero-lag rolling-scan OLEDs) to minimize microstutters in unsynchronized situations.
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Re: Mouse 125Hz vs 500Hz vs 1000Hz visible when strobed or G

Post by Trip » 09 Jun 2014, 10:00

Chief Blur Buster wrote:That works, if you can get the monitor Hz exactly the same as mouse Hz. In real life, the monitor might be 125.1Hz and the mouse might be 124.9Hz. This 0.2Hz difference is 1 stutter every 5 seconds. It could get closer than that though. Also, there will be a slowly slewing input lag effect right before each stutter, due to the drifting Hz difference. For a 125Hz mouse, for example -- you have mouse input lag slowly varying from 0ms through 8ms! Just right before the stutter, the input lag may be maximized/minimized (T+0/125sec or T+1/125sec), and right after the stutter, it becomes vice versa (minimized/maximized). A slowly-varying input lag is a Bad Thing.
Well I was assuming the mouse frequency to be a multiple of the monitor refresh rate. So if the mouse hz rate is at a 1000hz you could set the monitor frequency to any frequency that satisfies a 1000/n where n is a natural number. So 500hz, 333.333hz, 250hz, 125hz... etc. This way the maximum lag will be 1ms as long as the report rate stays stable. And slowly varying between 0-1ms of latency isn't much of a problem.
Chief Blur Buster wrote:Few game engines synchronize their framerate to the mouse Hz (Quake Live was one of them, I believe).
Not sure about this one I do know the maximum frequency of q3 engine games is a 1000 fps and the minimum 1fps. Every value in-between is calculated by the formula I already stated above (1000/n). Whether or not it is a separate timer or a sync to the report of the mouse I do not know but the engine is open source now so I guess you can look it up in the code.

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Re: Mouse 125Hz vs 500Hz vs 1000Hz visible when strobed or G

Post by flood » 09 Jun 2014, 17:14

Chief Blur Buster wrote:1 stutter every 5 seconds.
yes but shouldn't really be a problem unless you need perfectly smooth motion for a period of time greater than 5s. well for a 125hz mouse on 125hz screen, it could be a problem when the stutter occurs, but for a 500hz mouse, the occasional rare stutter would only be 2ms which isn't too much imo

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Re: Mouse 125Hz vs 500Hz vs 1000Hz visible when strobed or G

Post by Chief Blur Buster » 31 Jul 2014, 21:08

The other issue is the slowly-slewing input lag during tiny differences.

Right before a stutter, the input lag is highest (or lowest) and then right after the stutter, the input lag is now suddenly the lowest (or highest). The differentials grows or shrinks depending on the differential between the framerate and refreshrate (e.g. 125.0Hz aliasing with 125.1Hz during VSYNC ON). It may be better to have 30 microstutters per second rather than 1 stutter every 5 seconds, to keep average input lag human-predictable.
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