Fastest? ClientBundle vs plain URL images

Right now a large applicati开发者_开发知识库on I'm working on downloads all small images separately and usually on demand. About 1000 images ranging from 20 bytes to 40kbytes. I'm trying to figure out if there will be any client performance improvements by using a ClientBundle for the smaller most used ones. I'm putting the 'many connections high latency' issue for the side now and just concentrate on javascript/css/browser performance. Some of the images are used directly within CSS. Are there any performance improvements by "spriting" them vs using as usual? Some images are created as new Image(url). Is it better to leave them this way, move them into CSS and apply styles dinamically or load from a ClientBundle? Some actions have a result a setURL on an image. I've seen that the same code can be done with ClientBundle and it will probably set the dataURI for that image. Will doing improve performance or is it faster this way?

I'm specifically talking about runtime more than startup time, since this is an application which sees long usage times and all images will probably be cached in the first 10 minutes, so round-trip is not an issue (for now).

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Short answer is not really (for FF, chrome, safari, opera) BUT sometimes for IE (<9)!!!

Lets look at what client bundle does

Client bundle packages every image into one ...bundle... so that all you need is one http connection to get all of them... and it requires only one freshness lookup the next time you load your application. (rather than n times, n being the number of your tiny images.. really wasteful.)

So its clear that client bundle greatly improves your apps load time.

Runtime Performance

There maybe times when one particular image fails to get downloaded or gets lost over the internet. If you make 1000 connections, the probability of something going wrong increases (however little). FF, Chrome, Safari, Opera simply put the image not found logo and move on with the running. IE <9 however, will keep trying to get those particular images, using up one connection of the two its allowed. That really impacts performance in IE.

Other than that, there will be some performance improvement if you keep loading new widgets asynchronously and they end up downloading images at a later stage.

Jai