For best results:

1. Close all background applications and any open web browsers or tabs.
2. Turn off Wi-Fi and connect only one laptop or PC via ethernet cable to the modem and unplug any other devices connected to the modem while testing the speeds.
3. Testing on Wi-Fi will reduce the speeds, especially for devices which are far.
4. Make sure the PC/Laptop you are using is Gigabite capable.
5. The ethernet cables used during testing should be CAT5E or above as CAT5E would negotiate at 1000Mbps however, CAT6 would be more reliable for long distance.
6. Open linetest.nz 
7. Choose the nearest Vocus server, i.e., Auckland or Christchurch.
8. Repeat the test a couple of times to get an average speed.