Comment 8 for bug 1594924

Uploads are limited by Mongo / gridfs. If you upload the same file twice to the same resource name then the second upload is much faster, but if you change the file contents then it is about 3x to 4x slower. You can watch Mongo chomp CPU time as it does this.

Unfortunately having sorted that out, similar speedups aren't being seen on the download side, which is unexpected - I thought they were a similar code path but one was an HTTP PUT and the other a GET. Getting the profiler out again.