Q: When will BranchCache accelerate file access?

A: I talked about how BranchCache can accelerate file access in a TechEd North America session, "Inexpensively Speed Up Branch Office Access & Reduce Wasted Time by Implementing BranchCache," which you can watch online.

I explained how BranchCache is a trivial installation, accelerating network access to any file, folder, or application whose network protocol uses the SMB, HTTP/HTTPS, or BITS protocols. What isn't well known is that file access using BranchCache will not be accelerated until the third attempt at accessing the file.

BranchCache first requires the creation of content metadata, which are hashes of the content that are used during caching. This metadata creation is created at the first attempt to access the file. The content isn't cached locally until the second access attempt. Once cached locally after the second attempt, users will then see that file's access accelerated upon the third attempt to access the file.