Nginx - медленное отображение картинок

user www-data;
worker_rlimit_nofile 80000;
pid /var/run/nginx.pid;

events {
worker_connections 1000;
use epoll;
multi_accept on;
}

http {

##
# Basic Settings
##

sendfile on;
tcp_nopush on;
tcp_nodelay on;
client_header_timeout 1m;
client_body_timeout 10;
client_header_buffer_size 3k;
client_body_buffer_size 256k;
client_max_body_size 100m;
large_client_header_buffers 5 8k;
send_timeout 3;
keepalive_timeout 0;
reset_timedout_connection on;
server_tokens off;
server_name_in_redirect off;
server_names_hash_max_size 1024;
server_names_hash_bucket_size 64;
types_hash_max_size 2049;
open_file_cache_valid 30s;