Software

Much like the DeathAdder V4 Pro, the Viper V4 Pro is supported by Synapse 4, with an identical set of options. Yet unlike the DeathAdder V4 Pro, the Viper V4 Pro is also compatible with Synapse Web. Being a web driver, Synapse Web connects through WebHID and therefore will—at least as of now—only work on Chromium-based browsers such as Chrome or Edge. Compared to Synapse 4, certain features are missing either currently (such as profile synchronization) or categorically, as those functions realized through system-level drivers or services, which are installed as part of Synapse 4, cannot be deployed through the web driver. In particular, the Sensitivity Matcher and Smart Polling Rate Switcher features are not available within Synapse Web, and there is no macro support. Furthermore, the grouping of features is slightly different, as on Synapse Web, the Rotation function has been moved from the Advanced tab to its own tab.

All settings are accessible through five tabs. "Customize" houses button remapping, which also includes a HyperShift function to enable a second set of button maps that can be accessed upon pressing a dedicated shift button. The three indicator LEDs on the wireless dongle may be set to "Battery level," "Connection quality," "DPI stage," "Polling rate," or "Off." The "Performance" tab is used to adjust CPI for up to five color-coded levels, ranging from 100 to 50,000 CPI, and separately for the x- and y-axis. Since the sensor supports CPI adjustment in native steps of 1, truncating of non-native values is neither done nor possible, as any integer input value will be a native one. Polling rate can be set to 125, 500, 1000, 2000, 4000, or 8000 Hz. "Smart Polling Rate Switcher" will set the specified polling rate whenever a full-screen game is running. Detection is handled by Synapse's Game Manager service. A function called "Sensitivity Matcher" is also available. With this feature, one can match CPI between two mice. This is done by moving both mice together from left to right, and Synapse will propose a new "matched" CPI value when finished. The third tab, called "Power," enables one to set the idle time (in minutes) after which the mouse enters sleep mode, as well as the battery status percentage at which Low Power mode is enabled. Low Power mode lowers the maximum tracking speed from 930 IPS (22.86 m/s) to 550 IPS (13.97 m/s) and maximum acceleration from 90G to 40G. "Calibration" allows one to adjust the lift-off distance between three presets (low, medium, high), along with the option of setting up asymmetric cut-off. The "Advanced" tab contains an acceleration function, which allows setting different curve types, along with angle rotation adjustment. Both of these settings are saved to the on-board memory. Lastly, profile management is available, too. Macros may be created as part of the macro module.

All setting changes are saved live to the on-board memory, and the web driver is able to connect to both dongle and mouse.

Battery Life

Razer cites a battery life of up to 180 hours at 1000 Hz and up to 45 hours at 8000 Hz. Both Synapse 4 and the web driver include a percentage-based battery life indicator with single-digit accuracy, which is reliable and accurate. For every 2 hours of continuous usage at 8000 Hz, the indicator went down by 5%. Assuming linear consumption, around 40 hours of battery life therefore can be expected at 8000 Hz.

After not moving the mouse for a period of time set in Synapse 4 or the web driver, the Viper V4 Pro enters a sleep mode from which it can be woken up by moving the mouse, but not by clicking a main button.

Using the included USB Type-A to Type-C charging cable, I measured the charging speed during the constant current stage, which sits at 0.169 A. The battery has a capacity of 306 mAh (3.87 V) and utilizes a 3-pin JST connector.