Of course there is. For example.

However, since you weren't aware that ISO1600 film exists, it seems unlikely that you know for certain that the 40D is WAY better at that speed. Admittedly, 1600-speed film is very grainy. It is also possible to "push" film a couple of stops faster than its rated, and make up for it with longer development time, and some people used to use 800 speed or 400 speed film that way.

I don't take many pictures of fast-moving subjects, so I mostly used ISO25 or ISO50 film when I was doing a lot of photography. While we're on the subject, digital may be nearly as good as a 35mm film camera for image quality, but film is available in 6x7cm or 4x5in and the results from those negatives can be incredible. Digital is cheaper, and "good enough", but I still use my film cameras for stuff that I know is going to be enlarged -- typically my 6x7 Crown Graphics.