In the 1997 World Championship of Snooker, Ronnie O'Sullivan recorded the fastest maximum break in a time of 5 mins and 20 seconds.
However, who was the record-holder and with what time before O'Sullivan scored his 5:20?
James Wattana in his match versus Tony Drago made a full clearance in 7 minutes and 9 seconds at the British Open in 1992. At least, that's what this site says.
Stephen Hendry held the record during his first crucible maxi, 27 April 1995 the paper listed his prize money for everything in that tournament he would get and it was a lot of money, the £147000 for the 147 alone is more than most tournaments certainly at least then (Why it was scrapped by Hearn sadly), was hard reading back then always hated Hendry always backed Jimmy White... Don't recall the time he did it in but anyway it wouldn't have been close to Ronnie's. For the old videogameshow Games Master Hendry featured in one celebrity game, where he played a golf game. IIRC he failed his challenge, the host fellow scotsman Dominik Diamond asked him does he know how he'll spend his prize money?
I do not know if anyone beat his speed record between then till Ronnie's first and to date world record, if no one did then that's your answer, Stephen Hendry but I did not commit to memory the time.