need explaning about cpi/dpi

[avinin1]

hello,
i saw the privious threads that you guys opened and talking about the dpi/cpi and what is recommand, how it works etc.
but i cant really understand.
well, some says that when you have high dpi/cpi youve better priceision,
but some says that you need to have lower the cpi, something like 400-800 for old games like cs 1.6 beacause you use low resolution like 800x600.
in the other hand, steelseries company says that you need to set the sens in game to 1, windows to 6 and the most comfort cpi for you.
now, when i use this i am feel really comfort in game, but in desktop it too fast and i cant control it really. (desktop resolution 1024x1280, ingame 800x600)
some people says that is recommand to set high dpi and lower the desktop (windows) sens for get the feeling of the sens you like, but you have more dpi so it will be more precision..
but for expample, steelseries says, that when you set the default sens in windows -6/11- you will get 1:1 precision or something like this.
i dont understand, and really confusing..
please explain me that, and please - use normal english, dont tackle me with difficault and technical ones

thanks.

[Bullveyr]

OK, I'll try my best to put it in an easily understandable text but I will most likely fail.

CPI and DPI are the same thing but CPI (Counts per Inch) would be the correct term.
CPI means how much movement data the mouse sends when moved over the pad.
More CPI means that the mouse will send more data over the same distance and it also means that the smallest movement/data the mouse can recognize/send is lower which you can translate as "more precise".

But the CPI doesn't tell anything about how correct those data is and higher CPI have a tendency to send more wrong data.

In CS1.6 and other games which use the same mouse input methode (Source Engine for example) high CPI leads to negative acceleration, especially with low display resolutions.
Basically that means that the max. speed you can move your crosshair is limited but that's only an issue with lower sensitivities.

(I could tell you why but you wanted to keep it simple)

Forget what SteelSeries says, that's just to promote the ExactSense feature on the Ikari and Xai.

(Again, if you want I could go more into detail why it's BS)

You should set Windows to 6/11 because everything else is just another level of interpolation between your mouse and the game and you won't gain precision with higher CPI but lower Windows Sensitivity.
(again say it if you want more details)
Also Windows Settings don't affect more modern mouse implementations.


Bottom line, without going into details, is that you need enough CPI and all this theoretical benefits of higher CPI or whatever (besides some technical difficulties and drawbacks) don't mean much in the field.

So, allthough I say people should experiment with different settings, if your current settings feel fine for you there isn't something wrong about it.

PS: My Ingame CPI are also too slow for me on the desktop.

[Arc'xer]

I promised myself I wouldn't reply anymore to DPI threads because it just gets trolled, but.....

(A few posts I typed http://geekhack.org/showthread.php?t=10213, http://hardforum.com/showpost.php?p=1035470202&postcount=20, http://hardforum.com/showpost.php?p=1034229686&postcount=39)

[(Low DPI) x (Sensitivity for low DPI)] / High DPI

ex: 400 x 2 = 800(400 physical DPI 2 sensitivity) / 3200 = 0.25

So a 3200 DPI mouse to equate the same movement as a 400 DPI mouse with 2 sensitivity or a 1 sensitivity with 800 DPI needs to set the sensitivity to 0.25. And let's say the low DPI is around 30cm/360, then the 0.25 with 3200 will equal the same distance.

6/11 = 1:1 movement, 1 pixel = 1 pixel. Any more or less and you completely change the calculations based on the windows cursor multipliers.

Also just because it's 1:1 doesn't mean it won't interpolate. You either move a number of inches to match the movement. Or you set your sensitivity high enough that it skips or ignores pixels to achieve the end result.

ex: Say you got a 1000x1000 resolution. And you got a 500DPI mouse either it takes you two inches to cross the entire screen reading completely 1:1 movements or set your sensitivity to 2. To multiple the amount of movements 500*2 = 1000.

DPI/CPI = Dots per inch/Counts per inch.

If I have a 400DPI mouse every inch translates into 400 pixels of onscreen movement. So if I move 1 inch, 400 pixels are moved across the screen. But

In 1 inch you have 2.54 centimeters, 2.54/400 = 0.0635mm or 63.5μm(micrometers). That means with 1:1 movement you move physically 1 inch 400 pixels on screen and the sensor counts them once every 63.5μm.

The reason why people use low DPI in Counter-Crap is because it has an X/Y overlay it literally uses the monitor resolution as cursor movement. So if you too much DPI and low resolution then you get massive negative acceleration.

And the reason why Counter-Crap has low resolution gaming is not so much because of refresh rate but because lower resolution reduces recoil as ass backwards as it sounds, it does.

In any properly coded game there is a call called Directinput although Microsoft has separated the settings.http://msdn.microsoft.com/en-us/library/ee418864%28v=VS.85%29.aspx. Basically it allows you to take advantage of high DPI without negative acceleration like in the much older X/Y overlay.

People debate DPI too much and it's everywhere on the internet so much back and forth. The problem is most of these are or were people who played Counter-Crap and think it's the best game ever. So it's like a vicious cycle same bull**** keeps returning and low DPI, low DPI, etc.etc. and the same **** all the time.

This post which I mentioned above. Is a great example of how DPI allows you to be more precise and lower your master sensitivity.

The second example mentioned above. Shows you how DPI not only how you can lower your sensitivity much lower and maintain the same movements physically but gives you a much more precise and smoother feedback of movements.

And this is a great example of DPI image. Mice with high DPI When I saw that a long while back it fits exactly to what a mouse does with the whole X/Y positioning 2D system of the mouse.



The last example mentioned above is merely my explanations. I wish I typed it better.

In the calculation example at the top. You might be wondering what is the difference between 400/2 and 800/1 and 3200/0.25. Nothing all of them have the same amount of physical movements but with 3200 your not only reading 3200 physical pixels but 2.54/3200 = 0.00079375 or 793.75 nanometers. And reducing your master sensitivity, plus your also able to interact with the in between of the pixels.

Right now the highest DPI is 6000, if I'm not mistaken with the Roccat Kone 2. If we do the math 2.54/6000 = 423.333333.

What does the math mean like I mentioned above. To equate an inch of movement based on the DPI and 1:1 movement the sensor is reading at far smaller magnitudes of distance over a single inch.

But there is also one other issue and that's screen resolution. Most people base their DPI on the vertical and horizontal limits i.e. 1920x1200 or 2560x1600 etc.etc. What they forget is that in between those vertical and horizontal limits are millions of pixels.

Let's take 1920x1200 = 2,304,000 pixels. So if you have say 5000 DPI mouse, you can cover that in well under half-an inch. But inside you've got millions of pixels and ironically even though most people attribute FPS to aiming side-to-side and up-and-down. You also aim in between all that when your moving your mouse to aim.

Let's recap. Even though DPI = speed, it also = accuracy.

1. DPI provides more accuracy based on reading more physical movements based on the screen resolution.

2. DPI provides more speed which allows you to lower your master sensitivity.

3. DPI is physically more accurate because it reads far smaller magnitudes of distance based on an inch.

4. You can interact with the in between pixels like mentioned in the first example.

Now with that said I will say this. I've ignored m_yaw, m_pitch; I do not know how to correlate all those calculations into the math.

I also forgot to mention in my prior postings that some mice use interpolation of DPI to achieve higher levels. Which means that some sensors can't really read movements that small per se hence interpolation of DPI. And I also forgot to mention that for current technology for some mice makes higher DPI decrease the max tracing speed. But those are issues which could easily be solved in future engines.

One other thing is the whole myth that DPI is only for high sensitivity gamers. Just because you use a low sensitivity doesn't mean you can't take advantage of high DPI.

Some other calculators which provide some abstract information.

http://www.notalent.org/sensitivity/sensitivity.htm

http://www.csgnetwork.com/circlecalc.html

and

http://phoon.us/mouse/

[vicariouscheese]

lets not have other users have to scroll through this whole thing again

do you happen to know if tf2 runs on the same mouse inputs as cs1.6?  just asking as ive based all my mouse settings on cs info, so im running 400dpi on all my mice, 6/11, 3.0 in game, ~8inches/180

i like my current settings, but ive started playing sc2 and am considering upping my dpi, and just wondering if i should rethink all my fps settings or simply use 400 for fps and higher for rts.

[Bullveyr]

I promised myself I wouldn't reply anymore to DPI threads because it just gets trolled, but.....

Hehe, I know that feeling and I could start a discussion on some things you wrote but I will not.

[Arc'xer]

do you happen to know if tf2 runs on the same mouse inputs as cs1.6?  just asking as ive based all my mouse settings on cs info, so im running 400dpi on all my mice.

i like my current settings, but ive started playing sc2 and am considering upping my dpi, and just wondering if i should rethink all my fps settings or simply use 400 for fps and higher for rts.

Apparently(thread from a while back), I was wrong and it doesn't TF2 is source based with X/Y overlay.

Sc2 I don't know about high DPI. Someone came on this forum mentioning how dpi caused him issues in the game and it wasn't working right. Maybe blizzard fixed something during the beta. You need to test that out.

[vicariouscheese]

Apparently(thread from a while back), I was wrong and it doesn't TF2 is source based with X/Y overlay.

Sc2 I don't know about high DPI. Someone came on this forum mentioning how dpi caused him issues in the game and it wasn't working right. Maybe blizzard fixed something during the beta. You need to test that out.

i dont mean high like 4000, just higher than 400.  would probably try 800 or 1200, as i am used to moving around my desktop at 400 anyways

[Arc'xer]

i dont mean high like 4000, just higher than 400.  would probably try 800 or 1200, as i am used to moving around my desktop at 400 anyways

http://geekhack.org/showthread.php?t=9989

This was the thread either it was because he wasn't used to the higher speed or SC has a somewhat poor control over sensitivity. Either way try it out. It's probably an isolated incident but still if not then it's SC2's fault not yours.

[avinin1]

OK, I'll try my best to put it in an easily understandable text but I will most likely fail.

CPI and DPI are the same thing but CPI (Counts per Inch) would be the correct term.
CPI means how much movement data the mouse sends when moved over the pad.
More CPI means that the mouse will send more data over the same distance and it also means that the smallest movement/data the mouse can recognize/send is lower which you can translate as "more precise".

But the CPI doesn't tell anything about how correct those data is and higher CPI have a tendency to send more wrong data.

In CS1.6 and other games which use the same mouse input methode (Source Engine for example) high CPI leads to negative acceleration, especially with low display resolutions.
Basically that means that the max. speed you can move your crosshair is limited but that's only an issue with lower sensitivities.

(I could tell you why but you wanted to keep it simple)

Forget what SteelSeries says, that's just to promote the ExactSense feature on the Ikari and Xai.

(Again, if you want I could go more into detail why it's BS)

You should set Windows to 6/11 because everything else is just another level of interpolation between your mouse and the game and you won't gain precision with higher CPI but lower Windows Sensitivity.
(again say it if you want more details)
Also Windows Settings don't affect more modern mouse implementations.


Bottom line, without going into details, is that you need enough CPI and all this theoretical benefits of higher CPI or whatever (besides some technical difficulties and drawbacks) don't mean much in the field.

So, allthough I say people should experiment with different settings, if your current settings feel fine for you there isn't something wrong about it.

PS: My Ingame CPI are also too slow for me on the desktop.

ok,  i really wants to thank you about that you try your the best to explain it understanble, and you do it great btw.
if you can, i want to know more information about what you write.

I promised myself I wouldn't reply anymore to DPI threads because it just gets trolled, but.....

(A few posts I typed http://geekhack.org/showthread.php?t=10213, http://hardforum.com/showpost.php?p=1035470202&postcount=20, http://hardforum.com/showpost.php?p=1034229686&postcount=39)

[(Low DPI) x (Sensitivity for low DPI)] / High DPI

ex: 400 x 2 = 800(400 physical DPI 2 sensitivity) / 3200 = 0.25

So a 3200 DPI mouse to equate the same movement as a 400 DPI mouse with 2 sensitivity or a 1 sensitivity with 800 DPI needs to set the sensitivity to 0.25. And let's say the low DPI is around 30cm/360, then the 0.25 with 3200 will equal the same distance.

6/11 = 1:1 movement, 1 pixel = 1 pixel. Any more or less and you completely change the calculations based on the windows cursor multipliers.

Also just because it's 1:1 doesn't mean it won't interpolate. You either move a number of inches to match the movement. Or you set your sensitivity high enough that it skips or ignores pixels to achieve the end result.

ex: Say you got a 1000x1000 resolution. And you got a 500DPI mouse either it takes you two inches to cross the entire screen reading completely 1:1 movements or set your sensitivity to 2. To multiple the amount of movements 500*2 = 1000.

DPI/CPI = Dots per inch/Counts per inch.

If I have a 400DPI mouse every inch translates into 400 pixels of onscreen movement. So if I move 1 inch, 400 pixels are moved across the screen. But

In 1 inch you have 2.54 centimeters, 2.54/400 = 0.0635mm or 63.5μm(micrometers). That means with 1:1 movement you move physically 1 inch 400 pixels on screen and the sensor counts them once every 63.5μm.

The reason why people use low DPI in Counter-Crap is because it has an X/Y overlay it literally uses the monitor resolution as cursor movement. So if you too much DPI and low resolution then you get massive negative acceleration.

And the reason why Counter-Crap has low resolution gaming is not so much because of refresh rate but because lower resolution reduces recoil as ass backwards as it sounds, it does.

In any properly coded game there is a call called Directinput although Microsoft has separated the settings.http://msdn.microsoft.com/en-us/library/ee418864%28v=VS.85%29.aspx. Basically it allows you to take advantage of high DPI without negative acceleration like in the much older X/Y overlay.

People debate DPI too much and it's everywhere on the internet so much back and forth. The problem is most of these are or were people who played Counter-Crap and think it's the best game ever. So it's like a vicious cycle same bull**** keeps returning and low DPI, low DPI, etc.etc. and the same **** all the time.

This post which I mentioned above. Is a great example of how DPI allows you to be more precise and lower your master sensitivity.

The second example mentioned above. Shows you how DPI not only how you can lower your sensitivity much lower and maintain the same movements physically but gives you a much more precise and smoother feedback of movements.

And this is a great example of DPI image. Mice with high DPI When I saw that a long while back it fits exactly to what a mouse does with the whole X/Y positioning 2D system of the mouse.

Show Image

The last example mentioned above is merely my explanations. I wish I typed it better.

In the calculation example at the top. You might be wondering what is the difference between 400/2 and 800/1 and 3200/0.25. Nothing all of them have the same amount of physical movements but with 3200 your not only reading 3200 physical pixels but 2.54/3200 = 0.00079375 or 793.75 nanometers. And reducing your master sensitivity, plus your also able to interact with the in between of the pixels.

Right now the highest DPI is 6000, if I'm not mistaken with the Roccat Kone 2. If we do the math 2.54/6000 = 423.333333.

What does the math mean like I mentioned above. To equate an inch of movement based on the DPI and 1:1 movement the sensor is reading at far smaller magnitudes of distance over a single inch.

But there is also one other issue and that's screen resolution. Most people base their DPI on the vertical and horizontal limits i.e. 1920x1200 or 2560x1600 etc.etc. What they forget is that in between those vertical and horizontal limits are millions of pixels.

Let's take 1920x1200 = 2,304,000 pixels. So if you have say 5000 DPI mouse, you can cover that in well under half-an inch. But inside you've got millions of pixels and ironically even though most people attribute FPS to aiming side-to-side and up-and-down. You also aim in between all that when your moving your mouse to aim.

Let's recap. Even though DPI = speed, it also = accuracy.

1. DPI provides more accuracy based on reading more physical movements based on the screen resolution.

2. DPI provides more speed which allows you to lower your master sensitivity.

3. DPI is physically more accurate because it reads far smaller magnitudes of distance based on an inch.

4. You can interact with the in between pixels like mentioned in the first example.

Now with that said I will say this. I've ignored m_yaw, m_pitch; I do not know how to correlate all those calculations into the math.

I also forgot to mention in my prior postings that some mice use interpolation of DPI to achieve higher levels. Which means that some sensors can't really read movements that small per se hence interpolation of DPI. And I also forgot to mention that for current technology for some mice makes higher DPI decrease the max tracing speed. But those are issues which could easily be solved in future engines.

One other thing is the whole myth that DPI is only for high sensitivity gamers. Just because you use a low sensitivity doesn't mean you can't take advantage of high DPI.

Some other calculators which provide some abstract information.

http://www.notalent.org/sensitivity/sensitivity.htm

http://www.csgnetwork.com/circlecalc.html

and

http://phoon.us/mouse/

I really Appreciate your replay beacause you break your promise for helps - thanks alot, and i hope this thread will not be trolled.
your explain was really Detailed and you help me.

תודה רבה

[Rajagra]

I think that dots per inch and counts per inch are the same in a mousing context, because you are counting the dots that the mouse can resolve. One count = one dot of resolution. As far as I know, no manufacturers say that 2 DPI=1 CPI or any other silly multiplier like that, so the argument is pretty academic. But for this discussion let's use CPI, it's more unambiguous.

The mouse I'm using right now is a fixed 800cpi one. When you move it one inch it counts 800 changes in position. In the absence of further adjustment, it should move my cursor 800 screen pixels when I move it one inch. A quick check shows it indeed does (moving about one inch moves the cursor about half way across a screen 1920 pixels wide.) Hurrah!

My Windows cursor speed is 6/11, right in the middle. Looks like this is the 1:1 speed suggested elsewhere.

If I increase Windows cursor speed to 11/11 the mouse seems to go 3 times faster, not around 2X, so this slider doesn't seem to have a linear response. Why am I not surprised? (I have mouse acceleration disabled in the registry BTW.) Since this slider does not act linearly, that's another good reason to leave it at the default 6/11 if you can.

Next you have to deal with mouse driver settings. These might override the Windows settings, or act on top of them.

Then you might have a sensitivity setting inside applications (usually games.) Again, this can override the Windows settings, or act on top of them. Might also override the mouse driver settings, but that is less likely, depending on how the drivers work.

TL;DR Executive Summary: The mouse CPI determines how many screen pixels are moved per inch of mouse movement, after being multiplied by all the active software multipliers (Operating system multiplier, driver multiplier, application multiplier.)

[Arc'xer]

I think that dots per inch and counts per inch are the same in a mousing context, because you are counting the dots that the mouse can resolve. One count = one dot of resolution. As far as I know, no manufacturers say that 2 DPI=1 CPI or any other silly multiplier like that, so the argument is pretty academic. But for this discussion let's use CPI, it's more unambiguous.

While true, I'd rather they'd be separate. DPI is the inherent value of how much movement per inch. And CPI is the distance as to where it's counted in that inch.

800 DPI or 2.54cm(1 inch)/800 = 0.003175 or 31.75μm.

If I increase Windows cursor speed to 11/11 the mouse seems to go 3 times faster, not around 2X, so this slider doesn't seem to have a linear response. Why am I not surprised? (I have mouse acceleration disabled in the registry BTW.) Since this slider does not act linearly, that's another good reason to leave it at the default 6/11 if you can.

   1. 0.03125
   2. 0.0625
   3. 0.25
   4. 0.5
   5. 0.75
   6. 1.
   7. 1.5
   8. 2.
   9. 2.5
  10. 3.
  11. 3.5

[avinin1]

I dont understand something, I use for check these settings:
450cpi - 6windows sens.
or
1800cpi - 3windows sens.

but I dont know, 1800cpi -3windows sens feels better for me somehow.
but I worry about dont have 6 windows sens.
if its needed:
I using 19" monitor.
my ingame resolution is 800x600
my desktop resolution is 1024x1280

my mouse is steelseries xai (5001 max cpi).

[Bullveyr]

There is no need to discuss about the terms CPI and DPI, they both mean the same but CPI is the correct one.
Correct in the sense of "describing the function" and the sense of "used by the sensor manufacturers".

if you can, i want to know more information about what you write.

Neg. Acceleration in CS1.6:

The movement is determind by the movement of the Cursor on the Desktop.
You could say a "virtual desktop" is running in the background.

Every Frame the Game checks how much the Cursor has moved on that virtual desktop.
If the cursor has for example moved 200 pixels to the left (from the center) the game will translate that to the actual ingame movement (based on the ingame sensitivity settings).

The problem is that the cursor can't move over the edge of the desktop and the maximum movement is limited by the size of the virtual desktop.

For example:

Dsiplay Resolutions: 800*600
CPI: 400
Win Sens: 6/11
FPS: 100

If you move the mouse 1 Inch (in the time of 1 Frame) it will be at the edge of the desktop, if you move it 2 Inch in the same time the cursor will still be at the edge. The Game sees at as the same movement and therefore you will move your crosshair the same distance ingame allthough you move your mouse twice as much.

That's called Neg. Acceleration. (can also be caused by hardware issues)

It's affected by CPI (more = more accel.), display resolution (higer = less accel.), FPS (more = less accel.) and the general Windows Sensitivity Settings.

With the settings of this example the max. speed you can move your mouse without getting negative acceleration would be 2,54m/s.
If you would set your mouse to 1600 CPI it would be lowered to 0,635m/s.

Why you should keep Win Sens at 6/11:

Settings higher than 6/11 will multiply the movement data and you loose precision.
For example at 7/11 it will be multiplied by 1.5.
If the mouse sends 3 Counts it will get multiplied to 4.5 but because there are afaik no "half movement units" Windows can only send 4 or 5 units, both aren't linear to the mouse movement it will be inconsistent.

Same goes for settings below 6/11.
The Counts from the mouse will be multiplied with a factor below 1.

If you set it to 3/11 Windows will wait until the mouse has sent 4 counts before it sends movement data to the game.
You lose the theoretical gain of precision with higher CPI and it's also inconsistent (at least at 5/11).

That's why you should use the ingame settings, they work without this limitations.

Why SteelSeries is wrong:

The idea behind setting the ingame sensitivity to 1 and adjust your sensitivity with the CPI is to get rid of the ingame interpolation.

The smallest movement you can make (smallest rotation of your avatar) is limited.
This movement/rotation has to be done in a certain unit, if the movement determined by the mouse data and the sensitivity setting isn't exactly a multiple of that unit the actual movement of the Crosshair would be either too small or to big.

But the thing is that the smallest movement/rotation is very small which makes this interpolation pretty much negligible in real life.

For example the smallest movement in the Q3 Engine is 360/65536 or ~0,0055° (it's afaik the same in CS1.6 or the Doom 3 Engine).

As a comparison at 1920*1200 and real FOV 100 the center pixel on your screen represents about 0.0597° of the gaming world (horizontal).

That alone doesn't make this way "wrong", only pretty useless or non beneficial in practice.

But there is also the factor mouse itself, which also interpolates.

The sensor of the Xai only has CPI adjustment in 90 CPI steps, all other settings are interpolated by the MCU of the mouse, and because 1 count usually means more movement than the smallest movement the game can process this interpolation of the mouse is higher.

It only works with the real CPI settings of the mouse but that limits your choice of sensitivity options. 90 CPI more or less can mean much for how much you want to move your mouse.
Imho not worth for a benefit that only exists on paper.

Another interesting way would be to sync the display resolution with the CPI of your mouse so that a certain amount of counts sent by the mouse (for example 2 or 3) would always result in a crosshair movement of exactly 1 Pixel (you can calculate that).
But again your sensitivity options would be limited by the CPI steps of your mouse.
You would also not achieve that the exact same movement of the mouse (for example 1 Inch) would allways represent the exct same movement on the screen because the CPI of the mouse aren't 100% stable.


But people shouldn't take that stuff too serious, this are high level optimations which don't have to mean much for real gaming.

But there is also one other issue and that's screen resolution. Most people base their DPI on the vertical and horizontal limits i.e. 1920x1200 or 2560x1600 etc.etc. What they forget is that in between those vertical and horizontal limits are millions of pixels.

A conclusion from what I wrote above is that dependant on display resolution it's more like 10-20 for the game engine.


Edit:

I dont understand something, I use for check these settings:
450cpi - 6windows sens.
or
1800cpi - 3windows sens.

but I dont know, 1800cpi -3windows sens feels better for me somehow.
but I worry about dont have 6 windows sens.

Just because a setting is wrong on paper or theoretically bad doesn't mean much if those settings feel best for you.

In that case I would test how 1800 CPI and Win 6/11 feel with a 4 times lower ingame sensitivity, or are you talking about CS1.6 where those settings could lead to neg. accel.?

[avinin1]

There is no need to discuss about the terms CPI and DPI, they both mean the same but CPI is the correct one.
Correct in the sense of "describing the function" and the sense of "used by the sensor manufacturers".



Neg. Acceleration in CS1.6:

The movement is determind by the movement of the Cursor on the Desktop.
You could say a "virtual desktop" is running in the background.

Every Frame the Game checks how much the Cursor has moved on that virtual desktop.
If the cursor has for example moved 200 pixels to the left (from the center) the game will translate that to the actual ingame movement (based on the ingame sensitivity settings).

The problem is that the cursor can't move over the edge of the desktop and the maximum movement is limited by the size of the virtual desktop.

For example:

Dsiplay Resolutions: 800*600
CPI: 400
Win Sens: 6/11
FPS: 100

If you move the mouse 1 Inch (in the time of 1 Frame) it will be at the edge of the desktop, if you move it 2 Inch in the same time the cursor will still be at the edge. The Game sees at as the same movement and therefore you will move your crosshair the same distance ingame allthough you move your mouse twice as much.

That's called Neg. Acceleration. (can also be caused by hardware issues)

It's affected by CPI (more = more accel.), display resolution (higer = less accel.), FPS (more = less accel.) and the general Windows Sensitivity Settings.

With the settings of this example the max. speed you can move your mouse without getting negative acceleration would be 2,54m/s.
If you would set your mouse to 1600 CPI it would be lowered to 0,635m/s.

Why you should keep Win Sens at 6/11:

Settings higher than 6/11 will multiply the movement data and you loose precision.
For example at 7/11 it will be multiplied by 1.5.
If the mouse sends 3 Counts it will get multiplied to 4.5 but because there are afaik no "half movement units" Windows can only send 4 or 5 units, both aren't linear to the mouse movement it will be inconsistent.

Same goes for settings below 6/11.
The Counts from the mouse will be multiplied with a factor below 1.

If you set it to 3/11 Windows will wait until the mouse has sent 4 counts before it sends movement data to the game.
You lose the theoretical gain of precision with higher CPI and it's also inconsistent (at least at 5/11).

That's why you should use the ingame settings, they work without this limitations.

Why SteelSeries is wrong:

The idea behind setting the ingame sensitivity to 1 and adjust your sensitivity with the CPI is to get rid of the ingame interpolation.

The smallest movement you can make (smallest rotation of your avatar) is limited.
This movement/rotation has to be done in a certain unit, if the movement determined by the mouse data and the sensitivity setting isn't exactly a multiple of that unit the actual movement of the Crosshair would be either too small or to big.

But the thing is that the smallest movement/rotation is very small which makes this interpolation pretty much negligible in real life.

For example the smallest movement in the Q3 Engine is 360/65536 or ~0,0055° (it's afaik the same in CS1.6 or the Doom 3 Engine).

As a comparison at 1920*1200 and real FOV 100 the center pixel on your screen represents about 0.0597° of the gaming world (horizontal).

That alone doesn't make this way "wrong", only pretty useless or non beneficial in practice.

But there is also the factor mouse itself, which also interpolates.

The sensor of the Xai only has CPI adjustment in 90 CPI steps, all other settings are interpolated by the MCU of the mouse, and because 1 count usually means more movement than the smallest movement the game can process this interpolation of the mouse is higher.

It only works with the real CPI settings of the mouse but that limits your choice of sensitivity options. 90 CPI more or less can mean much for how much you want to move your mouse.
Imho not worth for a benefit that only exists on paper.

Another interesting way would be to sync the display resolution with the CPI of your mouse so that a certain amount of counts sent by the mouse (for example 2 or 3) would always result in a crosshair movement of exactly 1 Pixel (you can calculate that).
But again your sensitivity options would be limited by the CPI steps of your mouse.
You would also not achieve that the exact same movement of the mouse (for example 1 Inch) would allways represent the exct same movement on the screen because the CPI of the mouse aren't 100% stable.


But people shouldn't take that stuff too serious, this are high level optimations which don't have to mean much for real gaming.



A conclusion from what I wrote above is that dependant on display resolution it's more like 10-20 for the game engine.


Edit:


Just because a setting is wrong on paper or theoretically bad doesn't mean much if those settings feel best for you.

In that case I would test how 1800 CPI and Win 6/11 feel with a 4 times lower ingame sensitivity, or are you talking about CS1.6 where those settings could lead to neg. accel.?

If I uses 1800 with 6sens and adjustment my sens ingame its ok,
but in the desktop it too fast for me.

i want to know in theoretically, what is the "best" to use: (again, ingame resolution is 800x600, play only CS 1.6)
1)low cpi(beacause of low resolution ingame) ,ajustment ingame sens with 6 windows sens.
2)high cpi,adjustment ingame sens, lower windows sens.

if you can, explain me more about how to adjustment and get the perfect cpi setting.

[Bullveyr]

Theoretically the best would be Windows 6/11 and the CPI (multiple of 90) as high as possible without getting neg. acceleration.

I don't know how fast you move your mouse (or if neg. accel. is really an issue for you) but you could find out by running Enotus Mouse Test in the background (properly calibrated).

But again, what feels best for you is pretty much the best for you and Win Pointer Speed below 6/11 isn't something that bad.

btw what's your sensitivity (how much do you move your mouse for a 360 degree turn)?

[Rajagra]

I dont understand something, I use for check these settings:
450cpi - 6windows sens.
or
1800cpi - 3windows sens.

but I dont know, 1800cpi -3windows sens feels better for me somehow.
but I worry about dont have 6 windows sens.

Going by Arc'xer's table, a Windows setting of 3 is a 0.25 multiplier, i.e. divides speed by 4. So 1800/4=450 screen pixels per mouse inch, the same as using 450cpi@6Windows. So you are moving at the same speed but you are able to move in fraction of a pixel increments.

Normally that would be a waste, but:

• It might prevent juddering between pixels. If the mouse is borderline between two positions and flickers between them, this will definitely judder the mouse pointer with 450cpi@6Win. But at 1800cpi@3Win you may be juddering between pixels, so the mouse pointer will not move (75% probability). It will appear to be more stable.
• If the system uses any other multipliers >1 (driver or game), those fraction of a pixel movements given by 1800cpi@3Win will genuinely translate to smoother movement. But only if the position is passed on with full detail - I don't know if Windows does that or rounds the data down to integer values.

P.S. I'm reminded of the rule for old calculators: always multiply first and do the divisions later to avoid rounding errors. E.g. 1*3/3=1, but if you did 1/3*3 you would get 0.9999... (because 1/3=0.3333..., *3=0.9999...) You might be getting a similar effect.

[Glymbol]

http://geekhack.org/showpost.php?p=222355&postcount=27
There is no "pixel movement" in 3D.