Symptoms

List View/Editable List View created from large SQL table smart object loads too slow in IE9/11 (~60 seconds) whereas the same views are able to be opened in Chrome quickly (~6 seconds).
 

Diagnoses

This is known issue with K2 4.6.9 which has been addressed in K2 smartforms update rollup which is available upon request through K2 support.
You most likely may notice this issue with Editable List Views, as there is no option to enable paging for ELV. Normal (non-editable) List View has adjustable paging setting which is enabled by default and has a positive impact on performance. There is an existing feature request to add paging feature to ELV with no exact date for implementation as for now.

 

Resolution

Contact K2 support to request K2 smartforms update rollup which addresses this issue.