Software

Like every other Corsair product, the Katar Pro XT is compatible with iCUE, Corsair's powerful yet resource-hungry software suite. As always, all options are available through multiple list entries. CPI can be adjusted from 100–18,000 CPI in increments of 1 CPI and for up to three color-coded levels. Polling rate selection (125/250/500/1000 Hz) and macro and button remap functionality are available as well. Furthermore, surface calibration can be run, which lowers LOD beyond the default level. All settings are applied immediately, but only a select few save to the on-board memory: CPI levels, CPI colors, and hardware lighting settings (Static/Rainbow). Though not specifically mentioned by Corsair, polling rate and surface calibration are saved, too. Everything else requires iCUE to be running. On my system, the software has a RAM footprint of 300 MB on average when running in the foreground, along with a considerable CPU and GPU time cost and a footprint of 245 MB when minimized to the system tray. Upon exiting the application, several processes, including headset drivers despite me not owning a Corsair headset, keep running, totaling a RAM footprint of 42 MB on average and taking up CPU time even though iCUE isn't even running.

Lighting

The Katar Pro XT has but a single lighting zone, which is the scroll wheel. Without iCUE running, only two different lighting effects can be set and saved to the on-board memory: Static or Rainbow. While running iCUE, no less than 13 lighting effects are available, including shift, blink, gradient, and pulse effects, many of which can be further adjusted in terms of transition speed, direction, and color palette. Of course, the lighting can also be disabled altogether.

Color accuracy and vibrancy are excellent throughout. Here's a short demonstration video in which I'm going through the Rainbow, Color Pulse, Spiral Rainbow, and Visor lighting effects: