Originally Posted by Mergatroid
Really, what's with "disable a feature on your computer to get our hardware to work"?
Personally, I'm not having any problems with V-Sync, but I really hate it when a hardware vendor says to disable a feature on my computer to get their hardware to work. My answer is always "I think I'll just return your hardware and use someone else's hardware". V-Sync is there to eliminate tearing. Tearing in some games is really bad and those games must be played with v-sync on. I appreciate that this may just be a troubleshooting step, but manufacturers can't seriously expect gamers to drop v-sync just to use their hardware.
Having said that, V-Sync doesn't cause any problems on my computer, even with the RAT. So, perhaps the answer is somewhere else. If you're part of a small minority having this issue, then I would look elsewhere for the cause. I hate to say it, but some of the hardware on my computer didn't function properly until I had reinstalled Windows a couple of times. Even something like the order that resident software loads in can affect how some of it works. This is a pretty crappy problem to troubleshoot so I can sympathize with you for sure.
Save your rant for some other case.
It's very simple here :
In most engines, V-Sync causes input lag.
You disable V-Sync, and input lag is gone.
That happens with EVERY mouse brand.
It's just that Mad Catz/Razer/Logitech/Roccat/Zowie/Omgheadshot can do nothing about it because it's the way V-Sync works, and the way game engines are built.
Having said that, he should look into a way to resolve this, because it's his system config that makes the input lag, not the mouse.
I suggest checking if triple buffer is enabled, and check the value of frames to render ahead.