The Razer Lachesis configurator is an important tool because it enables you to configure and fine-tune the features of your mouse. Unfortunately, the tool is a bit confusing at first, Razer put way too many options into one window.
Pictured below is the base screen. It enables you to adjust the function of all nine buttons, and also enables you to turn buttons off in case you don't need them. This may come in handy in some games to prevent that you accidentally press one of the side buttons.
The polling rate can be adjusted to 125Hz (8ms), 500Hz (2ms) and 1000Hz (1ms), and the DPI can be switched from 125 to 4000 DPI. Another nice touch is that you can turn off the LED lights from the scroll button and Razer snake logo.
Two panels can be expanded on the left. The first one enables you to adjust the sensitivity levels of the X and Y axis, and there's also an option to turn acceleration on/off. The second panel lets you tweak pointer sensitivity, scroll speed and double-click speed.
The Lachesis has 32KB of onboard memory to store five profiles, you can even tie profiles to specific applications.
The final tab enables you to configure advanced functions for your mouse buttons. There are many possibilities here, you can select one of the basic commands (cut, paste, copy, save, undo, ...), additional commands (zoom in, zoom out, swap window, close window, show desktop, ...) or one of the media functions (volume up/down, play, stop, skip, ...).
Besides predefined commands or single keys, it's also possible to program macros for each of the nine buttons. This is useful if you want to do multiple actions at once.
The Razer software offers many functions, but may take some time to get used to.