LDAT v2

The Latency Display Analysis Tool (LDAT) is a smaller-than-a-matchbox device that might strike you as something that was put together as a school project. Do keep in mind this is a reviewer's tool, not a commercial product; so as long as it does its job properly, it doesn't have to look nice. The LDAT tool can be connected directly to the test system, or may be used on a secondary host PC. If the latter is the case, you have to use a properly modified external mouse to trigger the sensor; otherwise, the test system won't have a way to know when an input (mouse click) occurred. To use the mouse button built into the LDAT itself, which is the most reliable way to use the tool, it has to be connected directly to the test system, which is exactly what I did.


The electronics are placed inside a small metal case. Its external dimensions are a mere 27 x 35 x 17 mm.


The bottom of the device is covered in rubber, which is a wise design choice, as I wouldn't want to put anything else on top of my monitor's panel. There's a single cutout for the integrated light sensor. Attached to the device is an elastic strap, which conveniently affixes it to the monitor.


On the top of the LDAT device is where NVIDIA installed the 2-pin external mouse button connector, a status indicator LED, and a standalone mouse button. The latter is only available on the newest iteration of the LDAT tool, simply dubbed the LDAT v2. The aforementioned LED indicates the current mode of LDAT operation (purple is standby, blue is latency mode, green is active luminance monitoring, red is audio monitoring, and so on). The abbreviated device name is etched into its case.


The LDAT has two more ports. The Micro-USB port is used for PC connectivity, while the 3.5-mm audio port accepts headsets and external microphones. This port serves as an audio input, and a connected microphone can be used to listen for mouse clicks, which can then trigger the latency measurement. For this to work, the microphone has to be placed close to the mouse button.

LDAT Software

The LDAT software offers a fairly simple interface between the LDAT device and actual end-to-end system latency measurements. It calculates latency measurement statistics (minimum, average, maximum) and the standard deviation, and automatically logs data to a CSV file. Once testing is done, it shows the latency distribution and a Gaussian curve in real time. Arguably the most useful feature of the LDAT software is Auto Fire mode, which allows me to generate a large number of test samples in a short amount of time. Auto Fire mode works together with the built-in mouse button.

The software starts in so-called free-running mode, where the LDAT device watches the monitor's brightness in real time. Preparing it for testing with Auto Fire mode is done by selecting the desired number of samples (# Shots), adjusting the delay between each test (Shot Delay), and checking the Latency, Light, Auto Fire, and Mouse Emu boxes. After that, the only thing left to do is to go into the game and press the mouse button on the LDAT device, which has to be aligned with the flash indicator, or the muzzle flash, if the game in question doesn't have the flash indicator feature integrated.