Dual-Core Powerhouse

A dual-core processor is a single chip that contains two processor cores. It's the equivalent of having multiple processors on your motherboard, except that a dual-core processor lets you have two processors even if your motherboard has only one socket. Dual-core technology is great if you want to upgrade to multiple processors without replacing your entire system. But what if you're choosing between dual-core processors and a two-or four-socket system? Do dual-core processors really perform as well as two- or four-way single-core machines with an equivalent number of cores running at the same clock speed? I tried a few applications on equivalent single-core and dual-core configurations and found that AMD's dual-core processors performed as well as their single-core counterparts.

To test the effects of two cores on a single chip, I compared two four-core configurations. I used a NEWISYS 4300-E server on loan from AMD. The 4300-E is a four-way system, and each socket has its own memory. I tested four single-core Opteron 848 processors against two dual-core Opteron 875 processors. Both configurations had four processor cores, all running at 2.2GHz. I tried a few real-world processor-intensive tasks: encoding an MP3 file, encrypting a file, calculating Pi, and performing a join in Microsoft SQL Server.

For the MP3 file encoding, I encoded a 50MB WAV file to MP3 format by using the LAME MP3 encoder. For the encryption operation, I encrypted a 50MB file by using Gnu Privacy Guard (gpg) with a 1024-bit DSA encryption key. I calculated Pi to 4 million digits through a free program that implemented Chudnovskys's formula. And for the SQL Server join operation, I performed a join between a 100,000-row table and a 10,000-row table filled with randomly generated data. My dual-core configuration performed as well or slightly better than my single-core configuration for all four of the processor-intensive applications. For the full, Web-exclusive version of this article, as well as test results, go to http://www.windowsitpro.com, InstantDoc ID 48434.

Summary
AMD Opteron 875 X2 and 848

PROS: Dual-core processors are a good alternative to a motherboard with more sockets.

CONS: The highest-clock-speed single-core Opteron processors don't yet have a dual-core counterpart.

RATING: 4 out of 5

PRICE: Opteron 875: X2 $2149; Opteron 848: $698

RECOMMENDATION: In my tests, dual-core Opteron systems performed as well as single-core Opteron systems with equivalent cores and clock speeds for a few applications.

CONTACT: AMD * 408-749-4000 * http://www.amd.com