You probably don't want the base speed any higher, as it makes precision harder to control.
Instead, try increasing the acceleration. This will allow precision at low speeds but a 'fast whip' at high speeds.
You can do this manually in Terminal. The default value should be 2 [but isn't always]. Check the current value using
defaults read .GlobalPreferences com.apple.mouse.scaling
then adjust with
defaults write .GlobalPreferences com.apple.mouse.scaling 2
You'll need to log out to use the new value.
Alternatively, there's a 3rd party Control Panel which can adjust it on the fly- Mouse Acceleration Preference Pane (donationware) . [I've not tried this myself.]
Source: OSXDaily - Mouse Acceleration on a Mac – What it is and How to Adjust or Disable it