I quick search for "how many servers google" pops up 900,000 servers. My guess they would be CPU based. The current state of the art in Bitcoin mining is to us

I quick search for "how many servers google" pops up 900,000 servers. My guess they would be CPU based. The current state of the art in Bitcoin mining is to use ASICs designed for Bitcoin mining. ASICS have speed capable of reaching 60GH/S (60 billion hashes per second) or more, which is over 1,200 times faster than the average computer. So divide your 900,000 by 1200 and we get 750. So Googles entire CPU based servers pointed at Bitcoin would generate the equivelant of only 750 ASICs. I imagine some of the larger Bitcoin mining farms have many more ASICs than this.