I have a quite fast site but login with JFB connect is slow

I just registered on your site using Facebook. From the time I accepted permissions in the Facebook popup to the time I was brought to my profile, it took 9 seconds. That's not necessarily zippy, but it's not unreasonable. Can you let me know how long a new registration takes for you?

When I logged out and logged back in, the process took 4 seconds. This again seems reasonable. It's faster as there's less communication with Facebook required and the user doesn't have to be created within Joomla. Can you let me know how long a returning user login takes for you?

There's lots of variables that can increase login time, like the number of social profile plugins enabled (each slows things down slightly), whether debug mode in JFBConnect is enabled (off is faster) and other things. In general though, I wouldn't expect a huge improvement over the above, but we'll help however we can.

Finally, we always recommend testing from different computers, browsers, users and locations to see if the problem may be specific to one set of environment.

Thanks,
Alex

using a CDN so login time should not be different wherever you are on the globe

A CDN won't affect login performance. CDN's help distribute the content from your site that is loaded into user's browsers. The authentication process requires your server to go out and contact Facebook's servers to verify the user's identity and pull any profile information available about that user. That's dependent on the speed of your server, the speed of the connection of your server, and the distance of your server to the nearest Facebook datacenter. A CDN won't improve any of those.

That's why we recommend disabling as many social profile plugins as you can that you aren't using. Generally, a site only needs one social profile plugin to integrate with their profile extension of choice. That's in addition to general performance improvements, like disabling any system group plugins that aren't being used, that can speed up the whole site overall.

The other recommendation we'd have is to enable the "Show 'Logging In' message" message in the JFBConnect -> Configuration -> Facebook area. That will show a little popup to the user that the authentication process is proceeding, which can help users understand that things are progressing properly.

I hope that helps explain more, but if you have any questions, just let us know.

Thanks,
Alex