Nvidia LDAT & PCAT – What Are They?

How Does LDAT Actually Measure This?

It’s no surprise that LDAT uses some custom hardware, but how does it all work? Well, it’s mostly a lot simpler than you might think, despite it being incredibly complicated stuff. You get a special mouse and a camera. The idea is to measure mouse-to-photon timing. You click the mouse while playing a game, and the camera looks for a change in the video output.

So when you click your mouse, LDAT hardware will see the start of the signal (more on how in a moment), and when it sees a change in the on-screen information, it’ll time how long it took to get from that first stage to the action on screen. This means you’ll need to take the camera and place it somewhere on your gaming display where a change will happen. In most FPS games, this will be the end of the gun so you can see the muzzle flash. However, not all games have this, so you may need to get creative with the placement. However, some Nvidia Reflex titles have an implemented flash indicator feature, which is handy!

As you might expect, the mouse and the camera are wired together, independent of the PC, and I’m sure Nvidia has already done some sweet math to ensure the timing between the two devices is taken into account.

However, to ensure the measuring of the system isn’t adding to the latency, you would run both devices on a separate system. It doesn’t have to be a 2nd high-end PC though, a cheap laptop would do just fine, as it’s simply something to capture the output data from the LDAT, which simply plugs in via USB and feeds information to the FrameView 1.1 software.