It’s interesting that different browsers handle this fine…
Use case is: 31 megabyte animated gif, served from slow host. Same URL as in first post. Results?
Google Chrome: cripples browser perf during load, intermittently shows animation frames. Performance is at a crawl, to do anything in the browser is painfully slow.
Firefox: browser seems OK during load, shows animation frames at a decent clip as it loads. Performance seems OK, you can do anything while the image is loading.
IE: browser seems OK during load, shows animations at a rapid clip as it loads. Performance seems OK, you can do anything while the image is loading.
So this does seem to be a bit of a Chrome specific problem.