レギュレーションが一致してないが、まあ、勘弁。チューニングしまくり。
keep-aliveなし、並列500アクセスで5000RPS越え。RHES3、Xeon 3.2GHz

Server Software: Apache/2.0.46
Server Hostname: localhost
Server Port: 80

Document Path: /
Document Length: 2329 bytes

Concurrency Level: 500
Time taken for tests: 19.337415 seconds
Complete requests: 100000
Failed requests: 0
Write errors: 0
Total transferred: 258100000 bytes
HTML transferred: 232900000 bytes
Requests per second: 5171.32 [#/sec] (mean)
Time per request: 96.687 [ms] (mean)
Time per request: 0.193 [ms] (mean, across all concurrent requests)
Transfer rate: 13034.32 [Kbytes/sec] received