There is no reason why a gallery should be slower in Chrome than in any other browsers.
Try completely clearing your Chrome browser's cache before reloading your gallery's web page and check to see if you have any extensions installed in your Chrome browser which might somehow be contributing to the slow speed.
Also, check out our own demo galleries here to see if the same thing happens in your Chrome browser.
Demo Galleries: http://www.juicebox.net/demos/
If you continue to experience difficulties, please post the URL to one of your gallery pages and I'll take a look in Chrome and Firefox and let you know if I notice any difference myself.