for loop - apache在HipHop上的PHP基准测试

最近我用Apache benchmark (ab)对PHP的HipHop做了一个基准测试。

我期望PHP的HipHop比普通的apache2 web服务器运行得快，但结果却相反。

我使用这个脚本来测试服务器，

<?php
  $i=0;
  while($i < 1000000){
    echo 'Welcome to HipHop for PHP<br />';
    $i++;
  }
?>

和我使用这个ab命令进行基准测试:

ab -n 500 -c 5 [URL]

，我用这个命令来编译:

hphp/hphp hiphop1.php -k 1 -l 3

apache服务器的基准测试结果:

kiddo@kiddo-VirtualBox:~/dev/hiphop-php/doc$ ab -n 500 -c 5 http://localhost/hiphop1.php
This is ApacheBench, Version 2.3 <$Revision: 655654 $>
Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Licensed to The Apache Software Foundation, http://www.apache.org/
Benchmarking localhost (be patient)
Completed 100 requests
Completed 200 requests
Completed 300 requests
Completed 400 requests
Completed 500 requests
Finished 500 requests

Server Software:        Apache/2.2.16
Server Hostname:        localhost
Server Port:            80
Document Path:          /hiphop1.php
Document Length:        31000000 bytes
Concurrency Level:      5
Time taken for tests:   71.024 seconds
Complete requests:      500
Failed requests:        0
Write errors:           0
Total transferred:      15500095500 bytes
HTML transferred:       15500000000 bytes
Requests per second:    7.04 [#/sec] (mean)
Time per request:       710.240 [ms] (mean)
Time per request:       142.048 [ms] (mean, across all concurrent requests)
Transfer rate:          213122.37 [Kbytes/sec] received
Connection Times (ms)
              min  mean[+/-sd] median   max
Connect:        0    0   0.9      0      19
Processing:   505  708  61.1    694     960
Waiting:        0    0   3.3      0      67
Total:        505  708  61.1    695     960
Percentage of the requests served within a certain time (ms)
  50%    695
  66%    714
  75%    729
  80%    736
  90%    781
  95%    857
  98%    898
  99%    938
 100%    960 (longest request)

和PHP的HipHop基准:

kiddo@kiddo-VirtualBox:~/dev/hiphop-php/doc$ ab -n 500 -c 5 http://localhost:8080/hiphop1.php
This is ApacheBench, Version 2.3 <$Revision: 655654 $>
Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Licensed to The Apache Software Foundation, http://www.apache.org/
Benchmarking localhost (be patient)
Completed 100 requests
Completed 200 requests
Completed 300 requests
Completed 400 requests
Completed 500 requests
Finished 500 requests

Server Software:        
Server Hostname:        localhost
Server Port:            8080
Document Path:          /hiphop1.php
Document Length:        31000000 bytes
Concurrency Level:      5
Time taken for tests:   294.546 seconds
Complete requests:      500
Failed requests:        0
Write errors:           0
Total transferred:      15500052500 bytes
HTML transferred:       15500000000 bytes
Requests per second:    1.70 [#/sec] (mean)
Time per request:       2945.455 [ms] (mean)
Time per request:       589.091 [ms] (mean, across all concurrent requests)
Transfer rate:          51390.26 [Kbytes/sec] received
Connection Times (ms)
              min  mean[+/-sd] median   max
Connect:        0    0   1.6      0      20
Processing:  1515 2941 579.7   2919    4734
Waiting:     1452 2626 532.5   2609    4135
Total:       1515 2941 579.7   2919    4734
Percentage of the requests served within a certain time (ms)
  50%   2919
  66%   3147
  75%   3334
  80%   3448
  90%   3704
  95%   3937
  98%   4223
  99%   4394
 100%   4734 (longest request)

问题是，为什么HipHop在我的基准测试中运行较慢?

脚本测试有什么问题吗?