Thanks for replied.
I'm not using memcached with php but stand alone. I want to using nginx and memcached + php-fpm and eaccelerator.
i did tried this for my low traffic website and it works

[code]
server{
listen 80;
server_name www.lowtraffic.net;
access_log /var/log/nginx/lowtraffic.net.access_log;
error_log /var/log/nginx/lowtraffic.net.error_log;

root /home/lowtraffic/public_html/;

location / {
set $memcached_key $uri;
memcached_pass 127.0.0.1:11211;
default_type text/html;
error_page 404 405 = @fallback;
}

location ~* \.(gif|jpg|jpeg|png|css|js|ico)$ {
expires 30d;
access_log off;
}
location ~ \.php$ {
fastcgi_pass 127.0.0.1:9000;
fastcgi_index index.php;
fastcgi_param SCRIPT_FILENAME /home/lowtraffic/public_html/$fastcgi_script_name;
include fastcgi_params;
}
location @fallback {
rewrite ^ /index.php?q=$uri last;
}
}
[/code]

But when i using with >1000 visitors online on the same time, i got request time out.
What's wrong?