Sorry, that's just what I saw on Newegg for 8GB sticks. I did not intend to mislead. I am under the impression that most of Google's index is still served out

Sorry, that's just what I saw on Newegg for 8GB sticks. I did not intend to mislead. I am under the impression that most of Google's index is still served out of ram. Certainly I never saw any announcements to the contrary. The other poster also pointed out that sub-millisecond latencies are pretty unlikely. Considering all the diverse sets of data they need to pull from, it would be similarly difficult to believe that tens or hundreds of disk seeks could be carried out in a timely manner for each query to yield a 200 ms total calculation time. If I had to guess they have probably just started taking factors into account that they did not before. For example, perhaps they are measuring total internal latency rather than just the latency of a particular sub-system. Or maybe there are components that go to disk while the posting list lookups are done in RAM.