The processor

We always start off by talking about the CPU of choice. With the Xbox 360 out and developers beginning to focus their attention on multi-core programming, we clearly had to go with a dual core CPU. The discussion of whether dual core or single core CPUs are better for gaming has been resolved. Both ATI and NVIDIA have released drivers that work with multiple CPUs and this is just the beginning of what multi-core processors will have to offer in 2006. In fact, this is exactly what I predicted last year in my original Dual-Core AMD Opteron article.

Our pick for the best "under $400" dual-core CPU is the Socket 939 Opteron 165.

AMD Opteron 165 retail boxed
$350 - http://www.amd.com

Historically, Opterons have only been for workstations and servers. The Socket 940 Opterons had an on-board memory controller that required Registered DDR-RAM. This allowed these systems to use high-capacity RAM but added latency, making it a poor choice for most enthusiasts who were happy with a pair of DIMMs. The Socket 939 Opterons, however, are built around the "Toledo" core. This means that the Socket 939 Opterons are virtually identical to the flagship Athlon X2 4800+ CPUs. Importantly, this means you have support for conventional DDR-RAM. The only difference between the X2 4800+ (2.4GHz x2) and the Opteron 165 (1.8GHz) is the clockspeed.

At less than $400, you could also buy the entry-level Athlon64 X2 3800+ which runs at 2GHz. The difference is that the Opteron 165 offers a full 1MB cache per core instead of the 512KB of the 3800+. This improves the performance of the Opteron in traditional applications. It also turns out that the Toledo core is exceptionally robust meaning that it's possible to overclock the Opteron 165 while using air cooling. Most users are reporting overclocks to about 2.4GHz.

What about Pentium D 830?

We actually started our system building article using a Pentium D 830 that we had purchased at retail. After all, we've been using AMD processors in virtually all of our system building guides. The last time we used Intel was in our storage server, at a time then the i875P chipset was king. Unfortunately, our hands-on experience with the Pentium D was so disappointing that we felt unable to recommend it as a platform. The most striking difference between Intel and AMD is the heat and power consumption. With the Pentium D and the Intel boxed heatsink, running the CPU at full load produces a blow-dryer like effect. Not only does the CPU fan become annoyingly loud, but the air that it pushed out of the case is just as hot as the Xbox 360. In fact, before our Arctic Silver 5 reached its final equilibrium consistency with the Pentium D, we were getting constant data corruption and system lock-ups! CPU temperatures hovered in the high 60's initially (Celsius) and then dropped into the 50's. In contrast, the Opteron 165 was incredibly cool. Full load produced temperatures in the high 40's when using the stock heatsink and idle temperatures in the 30's.

Gaming and productivity comparisons between the AMD X2 Intel Pentium D have long shown the advantage of the X2 platform. In fact, the original 4200+ X2 (AMD's bottom-of-the-line dual core CPU at launch) outperformed Intel's flagship Pentium Extreme Edition 840 processor in most major applications. Intel has always been strong with its SSE implementation. One of the reasons we had been tempted to try the Pentium D was we expected the Pentium D to act as a great CPU for digital photography. In practice there ended up being very little difference between the two equally priced CPUs. Moreover, it was impossible to overclock the Pentium D.




Until Intel gets their dual core CPU act together, we're recommending AMD Opteron and Athlon64 X2 exclusively. Intel isn't faster, but it's definitely hotter which can lead to stability problems in a minimally ventilated system.