Playing Sherlock was the toughest: Benedict Cumberbatch

London: Actor Benedict Cumberbatch says playing genius detective Sherlock Holmes in TV series `Sherlock` made his brain hurt.

Cumberbatch, 35, said delivering the sleuth`s dazzling, lightning-fast speeches of deduction was more exhausting than any other role he has taken on, Daily Sun reported.

"Every deduction is hard. It`s always a painful process. There are all the details. It`s like a stream of consciousness of incredibly condensed information.

"He just goes at 100 miles an hour and it`s a huge speed to rush it out. It`s just hard, it`s hard graft ? there`s no other word for it," he said.

He also praised his co-star Martin Freeman, who plays Holmes` sidekick Watson.

"I`m not saying Martin has an easy job because what he does is with scalpel precision and he works incredibly hard.

"But he has a photographic memory, he looks at the lines in the morning and it`s learned, that`s it," he added.