What is the most efficient sleeping schedule for creative &productive lifestyle? how much helpful is polyphasic sleep of 20 minutes for every 4 hours?

Sleep: Generally sleeping 7-8 continuous hours of sleep is recommended. During polyphasic sleep you do have more time awake during the day but you don't completely have a chance to enter rem sleep, and if you do it is not long enough to be as beneficial as a full 7-8 hours would be. To be creative probably the 7-8 full hours, but to be productive polyphasic because you will have more time awake.