What's the best value dual core (DC) processor available at the moment (February 2006)? It's the Opteron 165. Indeed, its such good value that AMD recently put its price up because it was undercutting sales of poorer performing but more expensive Athlon 64 cpus.

What socket does the Opteron 165 use?

This is where things for the budget minded enthusiast get really interesting. Unlike 2xx and 8xx series Opterons (and older 1xx series Opterons) the Opteron 165 uses Socket 939, making it compatible with a huge range of excellent enthusiast Socket 939 motherboards.

What this means is that you don't have to use a specialist server motherboard with no overclocking features, and you don't have to use registered DDR ram.

What are the key specs?

Clock speed is 1.8GHz and importantly, each core has a full 1MB of L2 cache. This is a good thing, particularly when overclocking. Compare this to the more expensive AMD Athlon 64 X2 3800+ which only has 2x512KB L2 cache (admittedly it has a 2.0GHz clockspeed, but that's an irrelevancy once you start overclocking the Opteron 165).

What about Intel dual core processors?

The Opteron 165's main rivals in price are the cheaper Pentium D 920 and the more expensive Pentium D 930. Performance is on par with these Pentiums in most productivity type benchmarks, but superior in gaming and science computational benchmarks.

Overclocking the Opteron 165 - how does the Opteron 165 overclock?

A quick survey of the results available across the net shows that you should be able to hit 2.5GHz without increasing Vcore. Simply crank the bus frequency to 280MHz, drop the hypertransport multiplier and increase your memory frequency divider (unless you've got some really spectacular low latency RAM).

If you juice the Vcore you may be able to hit 2.6-2.7GHz. For a processor that sells for around US$325 that's some serious performance.