Intel Woodcrest, AMD's Opteron and Sun's UltraSparc T1: Server CPU Shoot-out

Apache/PHP/MySQL Performance

In our first review of the T2000, we took a look at the T2000 as a heavy Apache, MySQL and PHP web server (or SAMP web server) using a pretty complex weather report system. The PHP test script retrieves hourly-stored weather information out of a MySQL database, that can be overviewed by month. An 'opening page' displays all months that are stored in the database, and if you open a 'detail page', the month you have selected is submitted by query string parameters. Additional details about this test application are available if you would like to know more.

The problem with our first test was that with the caching file we are taking MySQL and PHP out of the equation most of the time, and emphasizing TCP/IP handling and Apache too much. As we want to get also an idea of the PHP/MySQL speed of the different CPUs, we decided to test with an uncached version, simulating the worst case of the application.

However, running the uncached version only means that we regenerate the PHP page with each request. We did enable the query cache in MySQL. A good webmaster knows that too many accesses to the database can completely wreck web server performance, thus, it is important to "shield" the database backend from too many concurrent accesses. The mod_deflate module was enabled to make gzip compression happen.

For benchmarking, httperf was used in conjunction with autobench, a Perl script written by Julian T. J. Midgley, designed to run httperf against a server several times, with the number of requests per second increasing with each iteration. The output from the program enables us to see exactly how well the system being tested performs as the workload is gradually increased until it becomes saturated. In each case, the server was benchmarked with 5 requests per connection. The client was connected via a gigabit connection to the server.

To interpret the graphs below precisely, you must know that the X-axis gives you the number of demanded requests and the Y-axis gives you the actual reply rate of the server. The first points all show the same performance for each server, as each server is capable of responding fast enough. Only one CPU with 2 (Opteron, Xeon) or 8 cores (Sun UltraSparc T1) was present in each server.



Intel's new Xeon wipes the floor here with the competition. Up to 75% faster than the 2.4 GHz Opteron, the new Xeon won't have any trouble with a 3 GHz Opteron. We have to investigate this further, but it seems that this is the result of massive 4 MB L2 cache and intrinsically better integer performance of Woodcrest. Additional tuning might push the T1 higher, but we are pretty sure it is not going to be a screamer in this benchmark.