A single-core Athlon 64 based on the 'San Diego' core. It has been released in May 2005 in the time-frame when dual-core CPU's also started to hit the market.

The fastest 'San Diego' single-core Athlon 64 is the 4000+ running at 2.4GHz with 1MB L2-cache. The 3700+ runs at 2.2GHz. > Read more