The last quarterfinalist will be determined and playoff venues decided in this weekend's final regular-season round of Super Rugby which will highlight again the unfairness of the tournament's conference system.

Seven quarterfinalists have already been determined, four from New Zealand, two from South Africa and one from Australia.

The defending champion and Christchurch-based Crusaders have sealed first place in the New Zealand conference and on the overall table, ensuring they will have home advantage as long as they stay alive in the playoffs.

The New South Wales Waratahs have clinched first place in the Australian conference. First place remains up for grabs in an African conference in which the Johannesburg-based Lions, finalists in each of the last two years, are three points ahead of Argentina's Jaguares.

The Lions play the Pretoria-based Bulls and the Jaguares face the Durban-based Sharks in intra-conference matches in the last round.

The African conference winner automatically qualifies for the playoffs and has home advantage until it faces a higher-ranked opponent.

Of the five wild-card playoff spots available, three have been secured by New Zealand teams. The Highlanders are safe as are the Hurricanes and Chiefs, who meet Friday in the opening match of the last round.

The Hurricanes have already beaten the Chiefs once during the regular season and the teams may meet again in next weekend's quarterfinals, either in Hamilton or Wellington.

The Hurricanes' Chris Boyd is the latest coach to denounce a system that gives home advantage to conference winners even when they accrue fewer championship points than wild-card teams. The Hurricanes currently have 50 points, placing them well ahead of the Waratahs with 44 and Lions with 41.

"The Crusaders are entrenched at No.1 and the Lions are going to finish top of their conference, the Waratahs are going to finish top of their conference and then the Chiefs and Hurricanes are going to finish fourth and fifth, or fifth and fourth," Boyd told Fairfax Media.

"The vagaries of the competition structure, given the pools, means that potentially both the Hurricanes and the Chiefs will finish higher, or thereabouts, than the Waratahs and Lions but don't enjoy the privilege of getting the home playoff, so that's an interesting feature of the competition."

The Dunedin-based Highlanders, with 40 points, have also secured a playoff berth ahead of their match on Saturday against the Melbourne Rebels. Their quarterfinal will be away from home but they will have to wait until the final round ends to learn whether it will be in Sydney, Johannesburg or Buenos Aires.

Scrumhalf Aaron Smith said the Highlanders aren't concerned about the quarterfinal venue.

"Playoff rugby is what it's all about," he said. "We're at the crunch end of the season, we've set ourselves up to be in the playoffs no matter what, which is nice. It's just a matter of where we're flying to."

The Waratahs will end the regular season against the ACT Brumbies, who have a slight chance of making the playoffs. The Rebels or Sharks will likely take the final quarterfinal spot.

A win would give the Waratahs a clean sweep of conference matches this season.

"The reality is you want to win games at this time of year," Waratahs assistant coach Chris Malone said. "You want to go into a quarterfinal on the back of a win against a good, tough side and that's really important for us."