How do you measure mouse lag?

[moeburn]

So right now, I do all my PC shooter gaming with one of these, a wireless Logitech M525:

 

 

But a friend of mine, who recently quit pc gaming, game me one of these, a wired Logitech MX500:

 

 

Supposedly the MX500 is one of the best mice for PC gaming.  I tried it, and I played worse at my favourite first person shooter than I am with my wireless mouse.  Yet supposedly, using a wireless mouse for serious gaming is a cardinal sin because of all the lag at transmitting those precious bits.  

 

So is there any way I can measure this lag?  Like pointing a high speed camera at my mouse&monitor, or something?  I would like to see if the reason I played worse on the MX500 is the same reason I type slower on a Dvorak keyboard - because I'm not used to it, but if I did get used to it, I could get much better than I ever could with a wireless mouse / QWERTY keyboard.  Or is the whole "gaming mouse" thing just placebo/hooey/snake oil, and the amount of lag introduced by a wireless mouse is not significant enough to affect even the most serious of gamers?

[Mindovermaster Moderator]

IMO, it doesn't depend on any statistics. It's all what you feel is best. If you are OK with the M525, use it.

[Scraggles]

Seriously. Just use what feels good to you. A good example, a lot of people use Mechanical keyboards and 'insist' on them for gaming. I use a wireless 'casual' keyboard for gaming and do better than my friends with 200$ keyboards. 

 

A lot of people just go for the 'cool' factor with this crap. Use what feels better to you, and don't change if you don't have to. 

[Andre S. Veteran]

So is there any way I can measure this lag?  Like pointing a high speed camera at my mouse&monitor, or something?

Precisely. Use a game that does very little buffering like Doom 3 BFG, disable VSync, and perform a few test runs with one mouse, then the other. See http://www.blurbusters.com/gsync/preview2/

 

If you don't have a high speed camera I don't know how you could measure this. Perhaps do many many tests with http://www.humanbenchmark.com/tests/reactiontime/index.php and compare your average reaction times with both mice, but that'd give quite inaccurate results at best.

 

Ideally you should be using a wired mouse with 1000hz polling rate. Typical mice poll at 125hz which introduces ~5ms of unnecessary input lag on average.

[Andre S. Veteran]

Just for those who think high polling rates are a gimmick, here's a quick drawing in Paint.NET where I draw two ellipses using a fast circular motion, one at 1000hz and one at 125hz:

 

As you can see, the ellipse on the left has some high-frequency detail, the line looks shaky and there's no obvious sampling point to be seen. The ellipse on the right is visibly a polygon made of a small number of points and smoothed out by Paint.NET's line drawing algorithm; it has no high frequency detail.

[Scraggles]

Just for those who think high polling rates are a gimmick, here's a quick drawing in Paint.NET where I draw two ellipses using a fast circular motion, one at 1000hz and one at 125hz:

 

As you can see, the ellipse on the left has some high-frequency detail, the line looks shaky and there's no obvious sampling point to be seen. The ellipse on the right is visibly a polygon made of a small number of points and smoothed out by Paint.NET's line drawing algorithm; it has no high frequency detail.

No one said it was a gimmick. It isn't. However a lot of people HATE high polling rates and a lot of people hate LOW. Just use what you like and you'll be better that way.

[Raa]

Unless you're competing professionally at a world tournament, I don't think you'll notice much of a difference - if any.

[Krome]

I try wireless/cordless mouse and dang... It's so hard to play the game with cordless.  Wired mouse is much more responsive.  No lag for me with the wired mouse.

[random_n]

Most of newer wireless sets from Logitech and Microsoft both have pretty good latency on the wireless path - responsive enough that you would have to measure your reaction time quite a few times to get anything empirical. Many of the older wireless sets (especially those targeted for home/office use) would have obvious latency problems and moving the mouse cursor was like dragging a marble around with an elastic band. Bluetooth models still have a bit of this problem, but the dedicated USB receivers are generally excellent.

 

The bigger differences now are between gaming and non-gaming mice. Even with many newer sets, a non-gaming oriented wireless mouse may go to sleep if left in one spot for more than a few seconds and require a large motion or button press to wake up again. This is a battery conserving measure, and easy to identify on the LED optic-based models by a flickering light underneath when lifted, turned upside down, or left alone (not so easy to tell on the laser ones, being invisible and all, but they do this too).

 

A gaming-targeted mouse may have higher sampling rates both internally and over the USB interface. Higher internal sampling will help pick up on mouse movements faster, interpret the motion more accurately, and reduce unintentional output (cursor drifting/jumping both in normal use and when lifting the mouse to reposition). Higher USB sampling rates gets those input actions to the computer in less time and can help smooth out the motion of the cursor to be more true to the motion that you're putting in by getting positional data there more frequently (angular vs smooth arcs in mspaint and so on). A wireless gaming mouse can easily have better characteristics than a wired mouse intended for an Excel jockey, but a wired gaming mouse is all-around ideal from a latency and reliability viewpoint.

 

I'll put in a big vote for the MX500/MX510/G400 series from a ton of personal experience, but comfort and familiarity accounts for a lot in any case. Just know that there are real advantages to using purpose-driven equipment here, and as with most technology, newer is generally better.