Symptoms

Formviewer Web parts taking time to render
 

Diagnoses

We have observed that the K2 Form viewer web parts take time to render on a SharePoint page. After the SharePoint page loads, we see the spinning image for a while before the HTML of the form starts rendering. This happens even with the simplest forms and views with few rules.

 

Resolution

We have logged a new TFS Item to enhance the performance.
There is a simple and easy workaround though.
Instead of using the K2 Form Viewer web part, make a use of the out of the box SharePoint page viewer web part instead.

This load much quicker.