Aero input lag confirmation?

hedgeshot · 20 Apr 2010

I was wondering if there has been much testing into Aero creating large amounts of input lag. A simple way to test is to have aero enabled and do a basic reaction time test and then repeat the test after disabling aero (system properties > advanced > performance > settings > "best performance"). Comparing results, Aero has added an additional ~50m/s of input lag.

Another curiosity is that having basically any single Aero feature enabled will result in the full amount of input lag. Is this a well known/documented problem?

(your mileage may vary depending on how consistent you are with reaction tests)

logicearth · 20 Apr 2010

No input lag here. With a margin of error the results were consistent regardless of Aero or Classic was enabled. In any case, an additional 50ms is so small the ability to perceived it is insignificantly. Getting humans to click a mouse button is a whole lot slower.

hedgeshot · 20 Apr 2010

It's fairly significant and noticeable as a PC Gamer. Going from 158m/s to 220m/s is basically the difference between great reflexes and average reflexes. It doesn't help having more lag between my keyboard/mouse and computer than my computer and the server. On XP I consistently get between 150 - 160m/s. On win7 w/o Aero I mirror that. With Aero enabled, I'm suddenly in the 220m/s+. I first noticed the lag when moving my mouse in Counter-Strike which led me to further investigate the problem.

Guess Aero will just have to stay disabled for now.

edit: Also, make sure not to go the personalize > classic route to disable it. Do the method I said and make sure all Aero features are disabled (ie all check boxes unchecked and UI will look like win95/98/2k).

logicearth · 20 Apr 2010

hedgeshot said:

I first noticed the lag when moving my mouse in Counter-Strike which led me to further investigate the problem.

Guess Aero will just have to stay disabled for now.

Except Aero is turned off when you run a full screen application like a game.

hedgeshot · 21 Apr 2010

I'll test with steam's in game browser and test results. I imagine there is a reason to 3dMark disabling aero, but perhaps I'm inferring too much.

logicearth · 21 Apr 2010

Are you using a USB mouse, keyboard?

hedgeshot · 21 Apr 2010

I'm using a Logitech G5 with newest setpoint drivers at 1000hz. Keyboard is also USB. I also had a friend test (though not very thoroughly) and came up with ~35m/s difference between aero enabled and disabled. I'll give it a whirl on my room mates laptop after I do some testing with steam.

logicearth · 21 Apr 2010

USB is directly affect to CPU usage. As the CPU has to manage the polling of all USB devices. Versus say PS/2 connection.

hedgeshot · 21 Apr 2010

I can confirm that aero is not running/creating input lag while in fullscreen game mode.