Worpress Custom Loop is very slow

Hi,

I am making a site with WP 3.8 and I have a big problem with WP Custom Loop. I want to list a certain category in a page. I also want to use three columns, because there are so many items. But when using three columns the page loads extremely slowly. Now there is one column in use and it loads quickly.

I wonder if anyone could help me.

Here is a test page: https://skabmagovat.fi/skabmagovat_2014/?page_id=4073