Performance: Better to use FastCGI or mod_php?

I would say that your Contact record spends a lot of time rendering the view.  Are there customizations to the Contacts module that could cause the Record view there to be re-rendered multiple times?  Do other modules (like Accounts, Cases, etc) have similar performance characteristics?

I used the complete page reload when starting the performance measurement, so you might have a point here. The Sugar instance has some additional fields and 3 addtional modules that are related to the contacts, so nothing out of the ordinary. Accounts, Leads and Calls (which has only notes as a subpanel) share the same loading times.

I used the complete page reload when starting the performance measurement, so you might have a point here. The Sugar instance has some additional fields and 3 addtional modules that are related to the contacts, so nothing out of the ordinary. Accounts, Leads and Calls (which has only notes as a subpanel) share the same loading times.

Ahh, yeah.  Full page reload is going to incur a JS hit as the app gets re-initialized and page gets re-rendered from scratch.  This is a limitation of single page applications. If you are clicking through application, (opening list view > select a record > edit > save, etc) then these operation are typically faster.

An end to end monitoring tool like New Relic can help identify the hotspots where users are having performance challenges. It allows you to set acceptable thresholds for requests that are used for detailed logging and reporting.  Sugar 7 has built in support for New Relic.

https://support.sugarcrm.com/Documentation/Sugar_Developer/Sugar_Developer_Guide_7.6/Performance_Tuning/Integrating_Suga…)

To your original question of mod_php versus FastCGI, I do not think I've seen a definitive recommendation.  I know that FastCGI is more typically seen with IIS on Windows for Sugar deployments.