I've been receiving complaints from clients about extreme download times (up to 30 minutes to view a 150MB file on a 20 mbps connection). So I decided to run some tests to see if this was being caused by a configuration issue, or something easy to resolve. (Testing results at the bottom of the page)
A little background info: Our core business utilizes pdf documents that have been enabled for shared review, reader extended, and then displayed within the browser. So I decided to take the same 50MB test file and create 4 versions of it. The original, one that was just reader extended, one that was just enabled for shared review, and one that was enabled for shared review AND reader extended. I then tested in 3 browsers, IE9, Firefox 3.6.17, and chrome 11.0. I used Reader X in all of the testing.
What I found out:
IE uses an active-x version of reader to display within the browser. This is the only browser in testing that used the active-x version and it does support streaming the file so that you can start working on the first page while the rest of the document is still downloading. BUT when a document is reader extended this feature does not work at all. You have to download the entire document before you can do anything. The viewer essentially freezes until it finishes downloading. Downloading in this psudo streaming method, it downloads MUCH slower. I'm talking 5 minutes to download a file that only takes 45 seconds if you click "Save Target As".
Firefox and Chrome both use the Plug-In version of the reader to display within the browser. This version does not support streaming of the file and instead forces you to download the entire file before viewing (even for non reader extended docs). The good news here is that on a Reader extended document, since it's not trying to stream the document it downloads much faster (more like 90 seconds for the same file that takes 45 seconds to download if you click "Save Target As").
I would tell our clients to use FF or Chrome, but that's in the hands of the IT departments, and most are using IE. As you can see the Active-X version of the viewer has by far the worst performance by far, and it's completely unbearable on files that are over 100 or 150MB. It would be nice if someone at Adobe could address this serious performance issue. I've even tried setting Fast Web View off and Speculative Downloading off, but the Active-X version still tries to display the first page and then stream the rest which results in a 3-5 minute download that should only take 45 seconds.