Generally speaking, sending packets less than 1KB is not efficient.

We're better to take some benchmarks see if removing extra buffer
is actually a good idea or not.

ext/zlib/zlib.c

@@ -1013,7 +1013,9 @@ int php_enable_output_compression(int buffer_size TSRMLS_DC)
 		return FAILURE;
 	}
 
-	php_ob_set_internal_handler(php_gzip_output_handler, buffer_size*3/2, "zlib output compression", 0 TSRMLS_CC);
+	if (OG(ob_nesting_level)==0)
+		php_start_ob_buffer(NULL, buffer_size, 0 TSRMLS_CC);
+	php_ob_set_internal_handler(php_gzip_output_handler, (uint)(buffer_size*3/2), "zlib output compression", 0 TSRMLS_CC);
 	if (ZLIBG(output_handler) && strlen(ZLIBG(output_handler))) {
 		php_start_ob_buffer_named(ZLIBG(output_handler), 0, 1 TSRMLS_CC);
 	}