Firefox downloads a ~15MB update that might cause unacceptably bad performance, or even not complete in an ordinary browsing session for users on slow connections.
Chrome downloads a assembly diff on the order of a few kilobytes, disassembles its own binary, patches and rebuilds on the client machine, completely transparently and without intervention of any sort.
It depends on what you're updating. If you're updating from 3.6 to 4.0, across 18 months of work, then yes.
If you're updating from Firefox 6 to Firefox 7, say, then the update for Firefox on Windows is 6.5MB. The Mac updates are bit bigger because they're updating fat binaries. You can see for yourself at http://releases.mozilla.org/pub/mozilla.org/firefox/releases... -- the partial.mar is the update from 6.0.2 to 7.0.
> Chrome downloads a assembly diff on the order of a few
> kilobytes
As of 2009, Chrome Courgette updates were about 80KB (compared to Chrome bsdiff updates of 700KB; bsdiff is what Firefox uses). This was for a total download of about 10MB.
At this point the total Chrome download size is a lot bigger; they have a lot more code; I would be surprised if their updates are smaller than 200KB. Or do you have data indicating otherwise?
One more thing. Courgette (Google's update tool) only works on x86 code last I checked. That may be one of the reasons they're not shipping a 64-bit Chrome even in environments where that's expected, like recent MacOS. And we'll see what happens when they port Chrome to ARM...
bsdiff, for all its faults, does not have those problems.
Now 200KB is still a good bit smaller than 6MB. And I agree that for users on slow connections this can be a problem. That problem is becoming pretty rare in the US, Europe, an East Asia, though.
