Here’s some interesting news on how long it takes for a single Google query.
Well, the answer is that it takes about 200ms, using the power of 1000 machines. Now, those 1000 machines could probably handle a whole bunch more queries in the same times frame so don’t get surprised.
Google Fellow Jeff Dean, in a keynote talk at WSDM 2009, shared some numbers about Google’s impressive growth run from 1999 to 2009. According to Dean, while both search queries and processing power have gone up by a factor of 1000, latency has gone down from around 1000ms to 200ms. Crawler updates now take minutes compared to months in 1999.
Another significant change was the switch to holding the complete search index in memory, resulting in the use of 1000 machines to handle a single query compared to just 12 previously.