Performance - Nginx Stream SSL Server Vs Nginx HTTPS Server

We have observed that the performance is very low in the Nginx Stream SSL Server compared to the Nginx HTTPS Server. Why is the Stream SSL Server giving low performance? Please find the Nginx configuration below and can anyone suggest ways to boost the performance of the Stream SSL Server?

**benchmark tool: Apache benchmark

events {
use epoll;
worker_connections 65536;
multi_accept on;
accept_mutex off;
}

Stream Server
=============
stream {
upstream https_server {
server 19.0.0.7:443;
}
server {
listen 1500 ssl ;
ssl_certificate cert/server.crt.pem;
ssl_certificate_key cert/server.key.pem;
ssl_client_certificate cert/RootCA.crt.pem;
ssl_asynch on;
proxy_pass https_server;
proxy_ssl on;
proxy_ssl_session_reuse off;
proxy_ssl_asynch on;
}
}

Backend Server
==============
http {
keepalive_timeout 50s;
connection_pool_size 1024;
keepalive_requests 10000;
access_log off;
server {
listen 443 ssl default_server;
ssl_protocols TLSv1.2;
ssl_certificate cert/server.crt.pem;
ssl_certificate_key cert/server.key.pem;
ssl_client_certificate cert/rootca.crt.pem;
ssl_session_cache off;
root /html;
index index.html index.htm index.nginx-debian.html;
server_name _;
location / {
try_files $uri $uri/ =404;
}
}
}**

Start by reproducing the comparison with Apache Benchmark using the Stream Server and Backend Server configurations shown in the issue. Inspect the SSL, proxy, and session-reuse settings in both paths; done means identifying the cause of the performance gap and documenting a measured improvement or a supported explanation.

Written by the indexing model from the issue text.