Software

The M3S Varun comes with its own lightweight software. All settings are distributed across six different tabs. The first tab includes button remapping, allowing one to rebind all buttons to mouse, keyboard, media, or macro functions. The second tab contains CPI adjustment at a range from 100–26,000 CPI in increments of 50, for up to five color-coded levels. CPI values can be entered manually, and upon confirmation any non-native values are automatically truncated to the next native value. Furthermore, polling rate can be set to 125, 500, 1000, or 2000 Hz, with the latter setting only being available when using the USB high-speed dongle. The third tab has a macro editor. The fourth tab houses lighting settings, which are detailed below. On the fifth page, Windows pointer settings along with various other settings are present. Lift-off distance can be set to either low or high. Furthermore, "Ripple" can be enabled or disabled, which introduces smoothing at higher CPI levels in order to lessen jitter at the cost of added motion delay. Likewise, if enabled, "MotionSync" lowers SPI timing jitter at the cost of increased motion delay, by an amount roughly equal to half of the set polling interval. "Angle Snap" may be enabled or disabled. "Debounce time" effectively controls click latency, with lower values decreasing latency but increasing the likelihood of eventual double-clicking and so-called slam clicking. The selection ranges from 0 to 20 ms and can be adjusted in increments of 1, with 8 ms being the default. Finally, a so-called "E-sports mode" is present, whose purpose is unclear. The sixth tab features miscellaneous software configuration options. Lastly, profile management is available, too.

All setting changes are saved live to the on-board memory, so the software does not need to be running (or be installed) all the time. On my system, the software had a RAM footprint of 23 MB on average when running in the foreground, which doesn't change when minimized, be it to the taskbar or system tray. Upon exiting the application, all processes are terminated, as they should be.

Lighting

The M3S Varun has a single physical zone for RGB lighting, which is the scroll wheel. A total of three pre-defined lighting effects are available in the software: Static Light, Breathing, and Rainbow. For most effects, brightness and the speed of transitions can be adjusted. Of course, the lighting can also be disabled altogether.

Color accuracy and vibrancy are decent throughout. Below is a short demonstration video showcasing the Breathing and Rainbow lighting effects:

Battery Life

Darmoshark provides two different battery life numbers: 80 hours when using a polling rate of 1000 Hz and 65 hours when using 2000 Hz. The percentage-based battery life indicator seemingly features single-digit accuracy, but the percentage varies seemingly at random, which makes it difficult to impossible to gauge anything. For the record, after 5 hours of continuous usage at both 2000 and 1000 Hz, the indicator first showed 74% and then 100% on every subsequent launch of the software.

Using the included USB Type-A to Type-C charging cable, I also measured the charging speed during the constant current stage, which sits at around 0.241 A. The battery has a capacity of 500 mAh (3.7 V) and utilizes a 3-pin JST connector.