People were encouraged to gather at lunchtime and use the service while Chorus and Dunedin City Council staff assessed how well the system performed.
Council appointee for the Digital Community Trust Cr Andrew Whiley said the testing had gone well, with speeds generally ranging between 70 and 95 megabits per second (Mbps) - depending on where people were standing and what device they had.
Public Wi-Fi offerings around the world tended to run at speeds between 4 and 5Mbps, he said.
Council corporate services group manager Sandy Graham said as a result of yesterday's load testing, the council would look at where additional receivers could be installed to remove the slow points.
Five receivers had so far been fitted around the Octagon, she said.
Cr Whiley said having free Wi-Fi at such high speed would prove to be ''just a huge asset to the city''.
''The whole gig concept we haven't really grasped yet. But it will allow a lot of things to happen in the Octagon.
''Kids will be able to come and do their homework, international travellers can skype their families back home. People can come in and do their work here.
''And what better place for that than the Octagon?''
Ms Graham said the gigabit Wi-Fi had come with an installation cost of about $11,000, although Chorus had contributed $10,000.
Monthly costs were $1519.25, which the council had budgeted for, up from the monthly cost of the Octagon's old Wi-Fi service of $570.42.
An official launch of the Octagon's gigabit Wi-Fi is planned for October 7.
