64-bit Linux: Ready for prime time?
Our tests of Opteron and Itanium servers show big performance gains today and promises of bigger gains to come
When running the Zeus Web server, the performance of the HP Itanium system was — while still slower — very close to the three Opterons, an indication that Apache on Red Hat Linux was not as optimized for the Itanium as Apache on SuSE Linux was optimized for the Opteron. (With more complex test suites, where each client was making multiple requests including large graphics, the HP fell a little further behind.) The Opterons all had Apache 1.3.26-105 installed, while the HP Itanium ran Apache 1.3.27-2. The table below shows the results running the Zeus Web server under 1,000 virtual clients.
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Other conclusions? In general, the tests show the Opteron has a slight edge over Itanium, at least for now. Among all my tests, the greatest difference between the highest-performing Opteron and the Itanium is about 20 percent. With the 1.3GHz and 1.5GHz Itanium 2 processors due by the time you read this, the advantage should be moving to the Itanium. In addition to increasing clock speed, the new chips double the L2 cache size to 6MB, compared to the 3MB in the HP Itanium system I tested.
Regardless of whether you choose Opteron or Itanium for Web serving, you’ll reap huge performance gains over 32-bit Xeon or Athlon. Even Apache on Itanium showed a 40 percent improvement over the performance of the dual Xeon system I used as a baseline.
Web server requests don’t stress an entire system as much as some other tasks. Opteron and Itanium systems should demonstrate even greater performance gains when handling very large databases, for example. Nevertheless, Web server performance is a good general indicator of the kinds of gains possible with 64-bit hardware and 64-bit code.
We should all look forward to the day when the applications we’re running now are available and optimized for Opteron and Itanium.