The three-day EB Games Expo at Sydney Olympic Park is the first chance Australian gamers have had to try two of the biggest releases in gaming history - Sony's PlayStation 4 and Microsoft's Xbox One.

Both consoles are set for release towards the end of November.

Organisers expect the expo to draw 40,000 people between Friday and Sunday, which would make it the biggest gaming event ever in the southern hemisphere.

Last year, the event drew 35,000.

"It's huge. It's ridiculous. It's kind of scary," said Hannah Tumbridge, 18, who travelled from the Gold Coast for the event.

The expo, her third, was "by far" the biggest yet, she added.

She said she had pre-ordered a PlayStation 4 but had been put off pre-ordering an Xbox One after initial concerns that users wouldn't be able to trade or lend games and would have to connect to the internet at least daily to keep playing.

Microsoft has since scrapped the plan in the face of a revolt from fans.

Another attendee, Canberra resident Andrew Haidon, 21, said he hadn't been deterred by the controversy and had both consoles on pre-order.

He said he was most interested in trying blockbuster titles such as Batman Arkham Origins, Battlefield 4 and Assassin's Creed IV: Black Flag, but wasn't too fussed about Call of Duty: Ghosts, which drew the biggest lines of the morning.

The Xbox One launches on November 22 with a price tag of $599.

The PlayStation 4 is released a week later on November 29, but is $50 cheaper at $549.