[Plugin: Quick Cache ( Speed Without Compromise )] Quick Cache not so quick

Quick Cache doesn’t seem to be working for me… I also have WP Optimize installed… Somehow my site is super slow and I was wondering if somebody can help me figure out why… That would be much appreciated.
The site is http://www.chaindlk.com and I am experiencing the slowness on both the backend and the frontend

http://ww.wp.xz.cn/extend/plugins/quick-cache/