Roger Federer believes it's becoming easier to play consistently as he prepares for his record 35th consecutive Grand Slam quarter-final at the Australian Open on Wednesday.

The all-time Grand Slam leader with 17 major titles is the epitome of consistency after defusing the big service of Canadian Milos Raonic in Monday's fourth round to take his place in the last eight.The Swiss great takes on 2008 runner-up Jo-Wilfried Tsonga in the quarters having not dropped serve in his 57 games at the tournament.

Federer last missed out on reaching a Slam quarter-final when beaten in the third round at the 2004 French Open by Brazilian Gustavo Kuerten.He says slower court conditions have made his feat more achievable.Obviously times have changed. Conditions have slowed down. That gives you an opportunity to be more consistent in all four majors, while before we had the clay court specialists, the fast court players," Federer said.

"Maybe I'm taking away things from myself a little bit, but I truly believe things are a bit easier to play more consistent today."A major part of the remarkable success Federer has achieved in his decorated career is his largely injury-free run."But then, of course, you have to stay injury-free. Whatever happens in a five-setter, if things don't go well physically for you, you'll pay the price and then you'll drop out of the tournament," he said.

"So many times, even if I did have problems, I did find a way to come through and survive and go deep in the tournament, often even win it."I'm happy to be in another one (quarter-final), but does it drive me? I don't know; I'm not sure. It's a nice record to have. Obviously as it's ongoing, you try to keep working at it."

Federer has yet to drop a set at the Open, while his major rivals, defending champion Novak Djokovic and Andy Murray, have had their wobbles.He was delighted with his form against the world number 15 Raonic, who has the most potent serve on the Tour. He tops the leaders at the tournament with 90 aces and has the fastest serve of 233 kilometres (144.8 miles) per hour.

Yet Federer dismissed Raonic in straight sets, without a service break.It was a very solid night, so I'm very happy. If I can maintain such a level of play, I give myself a chance of going deep in this tournament, which is obviously the goal," he said."I felt good out there. I was moving well, had good anticipation and reaction, which was key obviously on the return. In the third set I started to feel extremely good on the return.

"I played well. I think I played tactically well tonight and was able to keep the points short on my own service games, used the one-two punch."Federer leads Tsonga 8-3 in their meetings.