Disabled gzip compression in OpenSSL prior to 1.0.0 version.
This saves about 522K per connection.

src/event/ngx_event_openssl.c

diff --git a/src/event/ngx_event_openssl.c b/src/event/ngx_event_openssl.c
index 30e588c..4356a05 100644
--- a/src/event/ngx_event_openssl.c
+++ b/src/event/ngx_event_openssl.c
@@ -94,6 +94,24 @@
 
     OpenSSL_add_all_algorithms();
 
+#ifndef SSL_OP_NO_COMPRESSION
+    {
+    /*
+     * Disable gzip compression in OpenSSL prior to 1.0.0 version,
+     * this saves about 522K per connection.
+     */
+    int                 i, n;
+    STACK_OF(SSL_COMP)  *ssl_comp_methods;
+
+    ssl_comp_methods = SSL_COMP_get_compression_methods();
+    n = sk_SSL_COMP_num(ssl_comp_methods);
+
+    for (i = 0; i < n; i++) {
+        (void) sk_SSL_COMP_delete(ssl_comp_methods, i);
+    }
+    }
+#endif
+
     ngx_ssl_connection_index = SSL_get_ex_new_index(0, NULL, NULL, NULL, NULL);
 
     if (ngx_ssl_connection_index == -1) {