Help With Yii Caching On High Traffic Site: Yii 22 Req/sec. Vs Wordpress 6000 Req/sec.


We are about to substitute a Yii 1.1.13.e9e4a0 app on a high traffic site that currently runs Wordpress. With Nginx as the sole webserver, Wordpress does 6000 req/sec but the Yii application does only 22 req/sec with File Caching on.

The issue is that Yii always sends headers with a "No-store, no-cache" even though CFileCache is turned on, which is a problem because Nginx is configured to honor the backend instructions, and therefore there is never any caching at webserver (Nginx) level:

HTTP/1.1 200 OK => 

Server => nginx

Date => Tue, 24 Dec 2013 03:48:09 GMT

Content-Type => text/html

Connection => close

Vary => Accept-Encoding

Set-Cookie => session=c6ljnr0vlprrltn8dcfpg0m662; path=/

Expires => Thu, 19 Nov 1981 08:52:00 GMT

Cache-Control => no-store, no-cache, must-revalidate, post-check=0, pre-check=0

Pragma => no-cache

X-Nginx-Cache => MISS

Notice the last line with the Nginx cache miss.

Question is how can I get Yii headers to reflect caching status so that Nginx may in turn honor the backend and cache the output?

Any help on how to get Yii caching to work correctly will be greatly appreciated.