Latency decreases after switching mouse dpi. Why?

[Mr1991]

Electrical.

While there are electrical issues that interfere with this mouse, this isn't the problem with this specific thread and specific mouse.

Latency changes is a normal cause and effect of changing mouse DPI.

Just because sometimes it is electricity and sometimes it is not -- does not mean this specific original poster on this specific model of mouse is electrical related. Sometimes it is and sometimes it is not.

The fact is... there ARE non-electricity latency changes from changing mouse DPI. This is so much more common, that it's definitely incorrect to assume it's always electrical. I am a software developer, I make software, I have math understanding, and I understand why DPI changes can make lagfeel changes because you need to move a whole 1/dpi before the mouse will report. So when dpi=lower means a bigger time interval between polls, for a given mouse speed. Also, how fast you flick can also influence lag -- for example, moving only 1/4th of an inch (100/400ths of an inch) at 400dpi means you get only 100 mouse reports per second (1/100sec lag) instead of 400 mouse reports per second (1/400sec lag). So there's a LOT of variables, including dpi, mouse flick speed, smoothing algorithms, and other, that definitely add lag that are definitely NOT electrical related.

So please don't post misinformation that DPI-related lag issues are always electrical related.

Please post a new thread in the Electrical forum, this is not the electrical-related lag issues forum -- use the other forum for that.

Why did you delete my post? He clearly says this happens on every mouse he’s tried, not one particular one, also it does it in bios, so that rules out any Windows/os assumptions

[F1zus]

Why did you delete my post? He clearly says this happens on every mouse he’s tried, not one particular one, also it does it in bios, so that rules out any Windows/os assumptions

Because it's not electricity. What does electricity have to do with it? I connected the computer from battery and the result was the same. After changing the dpi to the same value, my mouse became sharper.
And this has nothing to do with the BIOS.

[Mr1991]

Why did you delete my post? He clearly says this happens on every mouse he’s tried, not one particular one, also it does it in bios, so that rules out any Windows/os assumptions

Because it's not electricity. What does electricity have to do with it? I connected the computer from battery and the result was the same. After changing the dpi to the same value, my mouse became sharper.
And this has nothing to do with the BIOS.

You realise a laptop still runs on electric right? And I brought up bios because the change in mouse movement is happening there too, which proves it’s not Windows

[Chief Blur Buster]

He clearly says this happens on every mouse he’s tried, not one particular one, also it does it in bios, so that rules out any Windows/os assumptions

Trying all mice is not proof yet.
Therefore I still deem a far better than 50-50 chance this is not electrical related.

Proof #1 that your claim of electrical-related is not proof:
- Original poster has a topic line "Latency decreases after switching mouse DPI".
This always happens even without EMI. This is a normal behaviour that most people don't notice but this poster notices. Even if this does not fix the problem, see Proof #3 below.

Note: Raising DPI generally typically lower latency (until your DPI is too high and the mouse-smoothing algorithm is mouse firmware kicks in, which can add back lag). But generally, on modern mice, 400 to 1600dpi doesn't add any smoothing-algorithm-related latencies.

Proof #2 is there's still a lot other unturned stones.
- I've seen mouse lag improve by installing a PCIe USB card
- I've seen mouse lag improve by swapping motherboards
- I've seen mouse lag improve by USB port roulette (using separate USB chips to power high-Hz keyboard and high-Hz mouse)
- I've seen mouse lag improve by uninstalling an audio driver for a crappy motherboard's builtin audio
- I've seen mouse lag being misblamed due to specific monitors and their settings.
- There's other unturned stones.
- The OP hasn't covered all of these stones yet

Proof #3 -- Electric-related answers are a forum rule violation unless posted in the other forum instead. Please read the forum rules. I've had to strictly enforce that rules due to past abuse. Although a fraction of forum members protested, more than 75% of forum members I discussed with (at the time) agreed with the rule of a separate forum for "lag from electrical causes" posts. This Proof #3 overrides everything even if you have convincing proof.

If the original poster wishes to move this thread over to the "Electrical" forum, have the original poster send me a PM. Or make a post over there and then link to this thread. That way it stays within the enforced rule of "No Electrical Posts in the Main Lag Forum". Re-post over there, and links are allowed between these two topic areas. However, the consensus (Even by mathematicans and YouTubers) disagrees with your assertion.

Just because something worked for you, doesn't mean it's a one-size-fits-all.
The royal flush factor here is the subject line -- and it's well known changing DPI changes latency based on simple mathematics alone (even when theres zero EMI). Not everyone can feel the lagfeel changes of changing DPI, but many do, and electronic measurements show latency changes. Even Battle(non)sense confirmed lag changes from DPI changes too:

phpBB [video]

It's plain science & physics. Anybody who passed high school math, will understand my explanation why DPI affects latency in a pure mathematical way, without needing to change the goalposts like 2+2=5!

Yes, additional factors can make it worse (and can include rare causes), but the topic thread title is pretty clear, and has a largely non-electrical related answer as the base answer, and the OP got a very clear mathematical answer that applies to all mice ever invented and ever released on the market -- switching mice won't fix the lag-upon-DPI-change effects fully (even if it gets affected, such as by different mouse smoothing algorithms and other). So your proof is a non-proof;

400dpi means that if your mouse moves less than 400 dots per inch per second, you get fewer mouse reports per second = higher latency for lower DPI during slow mouse movements (including, possibly, of course the initial "high lag" start of a flick turn, where your hand is still accelerating into its flick turn speed). 1600dpi means your 1/400 inch of movement will get four mouse reports instead of just one mouse report, including a mouse report that's 75% less laggy because a 1/1600inch movement was registered quickly before a 1/400sec inch of movement.

So raising DPI = lowers lag because there's more dots (metaphorical mileposts) along the inch in dpi="DOTS PER INCH". Imagine a horizontal mouse movement like going down a road full of mileposts, as a metaphor. The mouse sends a signal over the USB cable everytime it passes a dot (metaphorical mileposts) along the X dimension or the Y dimension. You have more dots (metaphorical mileposts) along an inch at 800dpi or 1600dpi than 400dpi. So you reach the next mouse dot (metaphorical milepost) quicker at higher DPI == less lag!

This is mathematically simple, literally junior high school math...

(Rheoretical question: Do you understand math? Think about this for a bit.)

Yes, there are many other variables, but this is the dominant component of the original poster topic subject line "Latency decreases after switching mouse dpi. Why?" and a very clear answer. It's easier than solving simple algebra such as y = ax² + bx + c.

When you re-post your answer in the correct Electrical forum, I'll copy-and-paste this answer.

[Thatweirdinputlag]

He clearly says this happens on every mouse he’s tried, not one particular one, also it does it in bios, so that rules out any Windows/os assumptions

Trying all mice is not proof yet.
Therefore I still deem a far better than 50-50 chance this is not electrical related.

Proof #1 that your claim of electrical-related is not proof:
- Original poster has a topic line "Latency decreases after switching mouse DPI".
This always happens even without EMI. This is a normal behaviour that most people don't notice but this poster notices. Even if this does not fix the problem, see Proof #3 below.

Note: Raising DPI generally typically lower latency (until your DPI is too high and the mouse-smoothing algorithm is mouse firmware kicks in, which can add back lag). But generally, on modern mice, 400 to 1600dpi doesn't add any smoothing-algorithm-related latencies.

Proof #2 is there's still a lot other unturned stones.
- I've seen mouse lag improve by installing a PCIe USB card
- I've seen mouse lag improve by swapping motherboards
- I've seen mouse lag improve by USB port roulette (using separate USB chips to power high-Hz keyboard and high-Hz mouse)
- I've seen mouse lag improve by uninstalling an audio driver for a crappy motherboard's builtin audio
- I've seen mouse lag being misblamed due to specific monitors and their settings.
- There's other unturned stones.
- The OP hasn't covered all of these stones yet

Proof #3 -- Electric-related answers are a forum rule violation unless posted in the other forum instead. Please read the forum rules. I've had to strictly enforce that rules due to past abuse. Although a fraction of forum members protested, more than 75% of forum members I discussed with (at the time) agreed with the rule of a separate forum for "lag from electrical causes" posts. This Proof #3 overrides everything even if you have convincing proof.

If the original poster wishes to move this thread over to the "Electrical" forum, have the original poster send me a PM. Or make a post over there and then link to this thread. That way it stays within the enforced rule of "No Electrical Posts in the Main Lag Forum". Re-post over there, and links are allowed between these two topic areas. However, the consensus (Even by mathematicans and YouTubers) disagrees with your assertion.

Just because something worked for you, doesn't mean it's a one-size-fits-all.
The royal flush factor here is the subject line -- and it's well known changing DPI changes latency based on simple mathematics alone (even when theres zero EMI). Not everyone can feel the lagfeel changes of changing DPI, but many do, and electronic measurements show latency changes. Even Battle(non)sense confirmed lag changes from DPI changes too:

phpBB [video]

It's plain science & physics. Anybody who passed high school math, will understand my explanation why DPI affects latency in a pure mathematical way, without needing to change the goalposts like 2+2=5!

Yes, additional factors can make it worse (and can include rare causes), but the topic thread title is pretty clear, and has a largely non-electrical related answer as the base answer, and the OP got a very clear mathematical answer that applies to all mice ever invented and ever released on the market -- switching mice won't fix the lag-upon-DPI-change effects fully (even if it gets affected, such as by different mouse smoothing algorithms and other). So your proof is a non-proof;

400dpi means that if your mouse moves less than 400 dots per inch per second, you get fewer mouse reports per second = higher latency for lower DPI during slow mouse movements (including, possibly, of course the initial "high lag" start of a flick turn, where your hand is still accelerating into its flick turn speed). 1600dpi means your 1/400 inch of movement will get four mouse reports instead of just one mouse report, including a mouse report that's 75% less laggy because a 1/1600inch movement was registered quickly before a 1/400sec inch of movement.

So raising DPI = lowers lag because there's more dots (metaphorical mileposts) along the inch in dpi="DOTS PER INCH". Imagine a horizontal mouse movement like going down a road full of mileposts, as a metaphor. The mouse sends a signal over the USB cable everytime it passes a dot (metaphorical mileposts) along the X dimension or the Y dimension. You have more dots (metaphorical mileposts) along an inch at 800dpi or 1600dpi than 400dpi. So you reach the next mouse dot (metaphorical milepost) quicker at higher DPI == less lag!

This is mathematically simple, literally junior high school math...

(Rheoretical question: Do you understand math? Think about this for a bit.)

Yes, there are many other variables, but this is the dominant component of the original poster topic subject line "Latency decreases after switching mouse dpi. Why?" and a very clear answer. It's easier than solving simple algebra such as y = ax² + bx + c.

When you re-post your answer in the correct Electrical forum, I'll copy-and-paste this answer.

I think the OP's post should be moved. This has nothing to do with the 1st initial mouse movement to "photon" delay test of battlenonesense, emphasis on the exaggerated use of the word "photon" to make the graph more legit. In my opinion, as much as I respect some of his other videos, this one was just not practical. Unless we are moving our mice 1-2 pixels at a time.

As far as I know, each sensor has its own native resolution. This determines the number of pixels laid on the tracking surface and the minimal number the sensor can see. That input is then taken and processed into movement data for the PC to display, and that is affected by its polling rate. DPI is applied after the data is already collected by digitally interpolating the output. It does not impact how the sensor itself collects data. The graph shows how the deviation between lower and upper values decreases as he moves towards the Native Resolution of the Deathadder V2 Pro, which I assume is "1600" since it's the default out of the box.

Sure, he has increased the distance between point 0 and the 1st dot in that inch by lowering the DPI, and hence it resulted in having an extreme value that completely painted his graph in a deceiving way. Once he takes a normal measurement count per dots moved instead of 1st to reach the dot or pixel then his entire theory would be rebutted and no more video for him to make. The life of Youtubers I guess.

"The mouse sends a signal over the USB cable every time it passes a dot" As metaphorical as someone can get, this is way too metaphorical that it took the reality out of the picture. The Mouse's sensor is essentially a small camera, it takes as many pictures per second "polling rate" as it's rated for, and it compares each picture with the previous one to determine how many pixels it has moved then it reports it to the PC.

What my assumption would be is, OP is experiencing a heavy mouse, which in reality the mouse itself is the same weight, but the perceived ease of the action of moving the cursor on the screen has changed, so when the brain perceives that slower or faster movement, it directly translates into a physical feeling that the mouse has become heavier or lighter. In other words, the weird phenomenon that a lot of us here are experiencing. And that's why I think the post should be moved!

[Chief Blur Buster]

"The mouse sends a signal over the USB cable every time it passes a dot" As metaphorical as someone can get, this is way too metaphorical that it took the reality out of the picture. The Mouse's sensor is essentially a small camera, it takes as many pictures per second "polling rate" as it's rated for, and it compares each picture with the previous one to determine how many pixels it has moved then it reports it to the PC.

Already know about the camera.

Depends on the mouse.

My post still stands.

My Razer 8KHz mouse permanently captures 24,000 frames per second (according to the Razer engineer that talked to me) and downsamples it to the pollrate. There is optional registers to adjust mouse smoothing, but the camera framerate will always remain 24 kiloframes per second, even at 400dpi, 800dpi, 1600dpi, 3200dpi, and even at 500Hz, 1000Hz, 2000Hz, 4000Hz, 8000Hz.

The mouse camera frame rate is constant at maximum for a very good reason, to prevent flick reliability failures at different pollrates and dpi (make sure "Enhance Pointer Precision" is OFF for mouse arrow circling to stay at the same speed at all poll rates on the same DPI). It's part why muscle memory is now more preservable at 500Hz versus 4000Hz, since the fast mouse-circling and fast flick-turns will generally turn the same distance (at the same sensitivity setting and DPI setting).

Regardless of the sensor frame rate, the mouse actually withholds reporting until sufficient movement (e.g. 1/400 inch for 400dpi, or 1/1600 inch for 1600dpi), it keeps internally tracking until then.

That's why low-vs-high DPI now behaves more identically in "edpi" behaviors (halve sensitivity for every dpi doubling) on newer mice running in newer software -- just with a minor latency differential due to more infrequent reporting at lower dpi (at least until you saturate your pollrate).

DPI-vs-latency observations is sufficiently common and not rare, so I'm leaving it here. Whether from the poll interval change, or from the

This is common enough that there's many pages and youtubes on this. So I deem it sufficiently common and not electrical related.

Yes, rare issues can influence, yes they do happen, but the common issue is the dominant lag determinant in the vast majority (not all) cases.

[Chief Blur Buster]

Because it's not electricity. What does electricity have to do with it? I connected the computer from battery and the result was the same. After changing the dpi to the same value, my mouse became sharper.
And this has nothing to do with the BIOS.

*** CORRECTIONS ADDED ***

1. F1zus is the original poster.
2. F1zus' topic title is "Latency decreases after switching mouse dpi. Why?"
3. F1zus' specific settings-change is additional proof that this is not electrical-related, since it's a pretty common solution elsewhere on even other systems that are known to not be electrical-interference-related.

F1zus can send me a private message telling me what to do with this thread, if desired. I've locked this thread since F1zus solved the problem, has had his question largely answered, and this thread has run its course. The recent posts are just a distraction. F1zus was simply looking for an explanation why dpi changes created these behaviors. And it's not electrical in this case.

Yes, there can be electrical reasons for mouse lags of various kinds, but that wasn't F1zus' problem. Also, generally, such electrical problems will generally be DPI-independent (electrical problem occuring at all dpi's regardless), such as EMI injecting into a mouse cable from external interference sources. DPI changes wouldn't fix that type of EMI anyway in nigh nearly all cases, and even it did, there's enough other checkboxes ticked to invalidate electrical at this juncture. Recent posts are now far beyond the threadcrapping threshold.

Enough checkboxes have clicked that it's (at this stage) just undesired thread derailment going on.

Commandeering/threadcrapping this thread into the whims away from the original poster, is counterproductive.

The Original Poster is king of their own threads and overrules when everything is pretty unambiguously clear. Non-original repliers trying to unproductively "extend" an existing thread in an already-solved/already-answered case -- can instead create their own thread rather than commandeering someone else' thread for your own purposes.

Sometimes there's a fine line, but Chief Blur Buster has made the final decision to deem this worthy of staying in the regular Input Lag forum. Common enough that there's high-viewcount youtubes about dpi and mouse latency, crissakes.

[Chief Blur Buster]

Unless we are moving our mice 1-2 pixels at a time.

Counterargument:

Refresh rates are getting higher. So is resolution too.

Often, we're slow tracking distant objects (e.g. distant snipers, distant airplanes, etc).

Moving a mouse 0.25 inch per second (slow track) is 100 reports per second at 400dpi.

100 reports is lower than current refresh rates (240Hz, 360Hz, 480Hz),

That's only 100 frames per second, in mouselook updates per second.

Grainy mouseturns is the fault of low DPI.

Low DPI sabotages your frame rate, creating a very grainy laggy feeling mouseturn that I can even feel laggy in.

Here's a test to try on your 240Hz+ display.
1. 400dpi and high sensitity. Now try turning slowly (slowtrack like long-aiming at slow moving distant objects). Grainy low framerate.
2. 3200dpi and 1/8 sensitivity. Now repeat the same thing. Fast flicks are unchanged and your muscle memory is unchanged (if it's a post-CSGO game), but slow flicks are so massively better.

I am no esports athlete, but on 240Hz+ OLED or 360Hz+ LCD at higher resolutions 1440p+, I can even clearly feel the DPI lag myself now!
In mere casual gaming! And it's very easy to mathematically explain.

The higher resolution means jitter can become more visible (e.g. becomes less smooth relative to keyboard strafe left/right).

Slow-tracking a distant object can be things like 0.25 inch/sec or 0.5 inch/sec, depending on what sensitivity setting you are using. When we're dealing with 4K 240Hz displays instead of 1080p 60Hz displays, low DPI is refresh rate race sabotage, period, full stop, no argument. Very highly human visible even in casual gaming, if your sensitivity settings is sufficient.

Homework.

1. Do you know why slow mouseturn isn't as smooth as keyboard strafe left/right? Bingo. Low DPI and its reportrate latencies.
My mouse turns are as perfectly smooth as keyboard strafe left/right, because in addition to recent sensor, clean mouse feet, and good mousepad, I've configured my mouse settings for modern post-CSGO era. Sometimes self-sabotage is necessary for less-dpi-friendly game compatibility (and preserving old muscle memories due to old games). But that's horse buggy era now, now that Valve discontinued CS:GO and newer high-DPI-friendly game engines are dominant.

2. Do you know why 100 frames per second is laggier than 480 frames per second? Are you a disbeliever of high frame rates? Low DPI = frame rate sabotage for slow mouse turns / mouse tracks (e.g. slow aim tracking distant objects, rather than common flick aimtrainer stuff)

Now you agree with me. (Even ignoring the crazy mousesmoothing software algorithms that sometimes filters and.or lags out the first fraction of a millisecond of movement, and such.)

Now that said, yes -- yes -- to improve things you had to lower DPI to match a game engine's nuances (e.g. imprecise mouse maths). Some experts could settings-out things to make 1600dpi sing in CS:GO, but 400-800dpi was more reliable. However, you can get universal muscle memory & mousefeel reliability at quad-digit DPI in newer engines thanks to more precise mouse mathematics in those newer engines. But this is all algorithmically-generated or reportrate-generated lag, with no rare/electrical component.

Old game engines had crappy mouse math, so CS:GO was best at 400-800dpi. Now, modern games like Valorant, CS2, Fortnite, sing pretty well at 1600dpi. Even esports athletes now often use 4-digit DPI instead of yesteryear old-engine recommendations.

Open your eyes mathematically.

EDIT: A private notification appeared about low 400 DPI being a useful defacto "snap-to-grid" for headshot line, where 400dpi clickpoints are easier to keep a perfectly horizontal line to keep all the headshots. Where, for example, flicking horizontally may stay perfectly horizontal for longer because you need a larger vertical mouse movement to get off the headshot line at low DPI. Fair, I'll allow that. But getting that benefit with a different tradeoff. And still doesn't make this rare/electrical....

Tradeoff effects happen often in esports on unanticipated consequences of an otherwise (normally) inferior setting that provides a hidden competitive advantage.

- Some people abuse BenQ AMA to make excess overdrive behave like tracer-highlighters (coronas = tracer effect) for a sniper staying stationary, for gamers who generally keep mostly stationary and just abuse the overdrive setting as a motion-highlighter cheat feature for specific gaming tactics.
- The converse also happens where tech advancements led to a downgrade in a lineitem: In CRT era, people used to track eyes more often before LCD motion blur made that nearly impossible with the first 60-75Hz LCDs twenty years ago; esports techniques change with the times.
- The decision to accept latency of a strobe backlight, to reduce motion blur, for certian crosshairsless games, where the Rainbow Six esports champion used strobing as a competitive advantage for fast-eyetracking during arena environments. (Faster human reaction time outweighed the increase in latency for certain types of gaming tactics).
- And this new information at hand; the snap-to-grid effect of low DPI may help staying on headshot line, if you're already previously well trained to this gaming tactic;

However, this is academic to the fact that DPI+lags generally are common in our audience and aren't electricity related here. When I read sites similar to Prosettings.net and others, it is clearly apparently that the longterm trend is towards higher DPI in the esports community in games other than CS:GO which was almost universally 400-800dpi, providing plenty of time to discover gaming tactics that only work at low DPI (like the snap-to-grid effect, utilized for a headshot line)