> Could you add

> open_file_cache max=1000 inactive=20s;
> open_file_cache_valid 30s;
> open_file_cache_min_uses 2;
> open_file_cache_errors on;

> and run just

> ab.exe -k -n 10000 -c 1

> to see if CreateFile() adds noticeable overhead ?

I have tested it with above configration, and there is nothing in the error.log.

C:\Program Files\Apache Software Foundation\Apache2.2\bin>ab.exe -k -n 10000 -
1 http://127.0.0.1/
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 127.0.0.1 (be patient)
Completed 1000 requests
Completed 2000 requests
Completed 3000 requests
Completed 4000 requests
Completed 5000 requests
Completed 6000 requests
Completed 7000 requests
Completed 8000 requests
Completed 9000 requests
Completed 10000 requests
Finished 10000 requests


Server Software: nginx/0.7.52
Server Hostname: 127.0.0.1
Server Port: 80

Document Path: /
Document Length: 151 bytes

Concurrency Level: 1
Time taken for tests: 1.750 seconds
Complete requests: 10000
Failed requests: 0
Write errors: 0
Keep-Alive requests: 10000
Total transferred: 3670000 bytes
HTML transferred: 1510000 bytes
Requests per second: 5714.29 [#/sec] (mean)
Time per request: 0.175 [ms] (mean)
Time per request: 0.175 [ms] (mean, across all concurrent requests)
Transfer rate: 2047.99 [Kbytes/sec] received

Connection Times (ms)
min mean[+/-sd] median max
Connect: 0 0 0.2 0 16
Processing: 0 0 1.6 0 16
Waiting: 0 0 1.3 0 16
Total: 0 0 1.6 0 16

Percentage of the requests served within a certain time (ms)
50% 0
66% 0
75% 0
80% 0
90% 0
95% 0
98% 0
99% 16
100% 16 (longest request)