Performance Problem

Hi all, I've been chasing what I think is the same performance issue for about a year and it's driving me batty. First off, the server is a dual core 2.8 P4 with 2G RAM running RHEL5 hosted at The Planet and is under very light load. This problem started last year while the server was RHEL4 and I completely rebuilt it with RHEL5. The PHP-based sites hosted on the server have shown intermittent performance issues when loading. A page might load fine 2 or 3 times, then take 5-10 seconds to complete the next page load. I've gone through everything top-to-bottom to try to eliminate possibilities: First thought was MySQL, so I took that out of the equation and tested pages that didn't use the database and that had no effect. Second though was httpd, so I compared straight HTML with PHP, and found the problem only occurred with the PHP pages. Straight html had no issues, so it's definitely a PHP problem. I've been compiling my own PHP with MySQL binary releases, so to make sure I wasn't causing the problem, I rolled back to RHEL5 httpd, php, and mysql. I even used the RPM's php.ini to try to rule everything out. To try and quantify the issue, I made a PHP page that just had a one-line echo and compared it with a regular html page and ran httperf tests with the following values (run from the server to take network issues out of the equation): httperf --hog --num-conn 100 --ra 10 --timeout 5 The html page always ran with no errors: Connection time [ms]: min 0.2 avg 0.4 max 13.7 median 0.5 stddev 1.4 Errors: total 0 client-timo 0 socket-timo 0 connrefused 0 connreset 0 On the other hand, the PHP on successive attempts: Connection rate: 6.9 conn/s (145.0 ms/conn, <=31 concurrent connections) Connection time [ms]: min 83.3 avg 585.4 max 2215.0 median 406.5 stddev 510.6 Reply status: 1xx=0 2xx=70 3xx=0 4xx=0 5xx=0 Errors: total 30 client-timo 30 socket-timo 0 connrefused 0 connreset 0 Connection rate: 10.0 conn/s (99.7 ms/conn, <=6 concurrent connections) Connection time [ms]: min 25.7 avg 232.1 max 1443.4 median 141.5 stddev 244.0 Reply status: 1xx=0 2xx=100 3xx=0 4xx=0 5xx=0 Errors: total 0 client-timo 0 socket-timo 0 connrefused 0 connreset 0 Connection rate: 6.8 conn/s (148.0 ms/conn, <=47 concurrent connections) Connection time [ms]: min 107.4 avg 1066.1 max 1989.7 median 1201.5 stddev 519.5 Reply status: 1xx=0 2xx=22 3xx=0 4xx=0 5xx=0 Errors: total 78 client-timo 78 socket-timo 0 connrefused 0 connreset 0 As you can see, it's all over the place and it shouldn't really be taxing it enough to cause problems on that server. At this point, I don't know what else to do. If anyone can shed any light on this, I'd be forever grateful. I'll try anything and do whatever I can on my end to fix this. Thanks in advance.