While testing to make sure some javascript was properly working cross-browser, for an upload-progress indicator, I came upon a strange issue. The script seemed to be functioning properly but the uploads were taking forever to complete in IE6…
That didn’t seem right. It seemed like the browser would have something to do with efficiency but surely the primary bottlenecks (for something so dramatic) would be network related, but I was running the uploads off of the local network and wasn’t seeing the same type of issues in any other browser/OS.
With a bit more digging, the culprit was found.
This issue occurs because the default Winsock Send buffer is 8 kilobytes (KB), and therefore Internet Explorer supplies the data in 8 KB chunks. On an average network, this equals approximately 80 KB per second (KBps), regardless of network bandwidth.
So, you might not bump into this if you’re running on a not-so-fast connection, but if your users are typically going to be on something nice and quick – there’s a fix here (via some registry changes). Of course, the real fix is: update IE to the most recent version or just use Firefox.
