Thank you Agentzh.

I did a test with a simple set up. Amazon large machine with nginx sering a file from disk and in another set-up serving teh same file from a local memcached. To my surprise I do not see any difference in the performance. They were equal. So given the complexity of memcache in between I see not having memcache is better.

How could be this possible? I did test to 100, 300 and 500 concurrent users with 89kb of html file for 1 minute using sieze.

Regards
Amod