I do craft development on a local setup (using a virtual .dev host). The one very annoying issue I experienced is a large latency (~10s) I get while using the backend – f.e. saving an fresh entry or creating a new field. The latency vanishes as soon as I disconnect from the internet. Is there any "call home" function build into craft that causes the delay?
In the end I resolved my problem - which was unfortunately not related to craft at all. For unknown reasons there it was just quite evident visible.
Facts: I'm running MAMP on a local OSX (Yosemite) setup. My craft website is running on a virtual domain pointing to localhost. PHP 5.4 Mysql 5.x Craft 2.3.26 Pro version
Issue: Long latency (~10s) when editing an entry/adding stuff.
Solution: In the end it was related to OSX issues with resolving a vhost address and resulting in loopbacks. A detailed description of the issue und how to resolve it can be found on stackoverflow.
Craft does use cURL to connect to web services at buildwithcraft.com and there is a 30 second timeout if there is no response from our end.
It will then cache that there was a connection error and not attempt to call home again for the next 5 minutes.
If there is a cURL configuration problem, then check your
craft/storage/runtime/logs folder for any
[warning] entries and it will tell you what the error message is.