使用 Apache 的 ab 工具测试了下几个网站的并发
本机配置

本地测试 echo 'hello world'
./ab -c10 -n1000 http://localhost/helloworld.php

Server Software: nginx/1.11.5
Server Hostname: wp.a.cc
Server Port: 80
Document Path: /helloworld.php
Document Length: 25 bytes
Concurrency Level: 10
Time taken for tests: 1.041 seconds
Complete requests: 1000
Failed requests: 12
(Connect: 0, Receive: 0, Length: 12, Exceptions: 0)
Non-2xx responses: 1000
Total transferred: 219284 bytes
HTML transferred: 26776 bytes
Requests per second: 960.29 [#/sec] (mean)
Time per request: 10.414 [ms] (mean)
Time per request: 1.041 [ms] (mean, across all concurrent requests)
Transfer rate: 205.64 [Kbytes/sec] received
Connection Times (ms)
min mean[+/-sd] median max
Connect: 0 0 0.4 0 1
Processing: 2 10 4.7 9 22
Waiting: 2 10 4.6 8 22
Total: 3 10 4.7 9 22
测试 phpinfo()
./ab -c10 -n1000 http://localhost/phpinfo.php

Server Software: nginx/1.11.5
Server Hostname: wp.a.cc
Server Port: 80
Document Path: /phpinfo.php
Document Length: 98215 bytes
Concurrency Level: 10
Time taken for tests: 4.408 seconds
Complete requests: 1000
Failed requests: 107
(Connect: 0, Receive: 0, Length: 107, Exceptions: 0)
Non-2xx responses: 17
Total transferred: 96733608 bytes
HTML transferred: 96548186 bytes
Requests per second: 226.85 [#/sec] (mean)
Time per request: 44.083 [ms] (mean)
Time per request: 4.408 [ms] (mean, across all concurrent requests)
Transfer rate: 21429.39 [Kbytes/sec] received
Connection Times (ms)
min mean[+/-sd] median max
Connect: 0 0 0.4 0 1
Processing: 10 44 8.9 43 78
Waiting: 9 43 8.9 42 78
Total: 10 44 8.9 43 78
测试新装 WordPress
./ab -c10 -n100 http://localhost/wordpress/

Server Software: nginx/1.11.5
Server Hostname: wp.a.cc
Server Port: 80
Document Path: /wordpress/
Document Length: 52976 bytes
Concurrency Level: 10
Time taken for tests: 45.738 seconds
Complete requests: 100
Failed requests: 0
Total transferred: 5323100 bytes
HTML transferred: 5297600 bytes
Requests per second: 2.19 [#/sec] (mean)
Time per request: 4573.759 [ms] (mean)
Time per request: 457.376 [ms] (mean, across all concurrent requests)
Transfer rate: 113.66 [Kbytes/sec] received
Connection Times (ms)
min mean[+/-sd] median max
Connect: 0 0 0.5 0 1
Processing: 447 4366 790.2 4507 5239
Waiting: 446 4366 790.2 4507 5239
Total: 447 4367 790.2 4507 5240
WordPress 安装 WP Super Cache 缓存插件
./ab -c10 -n100 http://localhost/wordpress/

Server Software: nginx/1.11.5
Server Hostname: wp.a.cc
Server Port: 80
Document Path: /wordpress/
Document Length: 53120 bytes
Concurrency Level: 10
Time taken for tests: 2.721 seconds
Complete requests: 100
Failed requests: 0
Total transferred: 5338000 bytes
HTML transferred: 5312000 bytes
Requests per second: 36.75 [#/sec] (mean)
Time per request: 272.131 [ms] (mean)
Time per request: 27.213 [ms] (mean, across all concurrent requests)
Transfer rate: 1915.58 [Kbytes/sec] received
Connection Times (ms)
min mean[+/-sd] median max
Connect: 0 0 0.4 0 1
Processing: 32 260 47.2 268 328
Waiting: 32 260 47.2 268 328
Total: 32 261 47.2 269 328