AMD today launched the dual-core Athlon 64 X2 3800+ and additionally they also released the Sempron 3400+. This entry-level processor is made on the 90nm process and runs at 2GHz with 256KB L2 cache. Its maximum thermal power is 62W and it ships for $137 in 1,000 unit lots.
The major "physical" difference between the Sempron 3300+ and 3400+ is the 3400+'s 256KBof L2 cache compared to the Sempron 3300+'s 128KB L2 cache. Each processor shares the same 2GHz clock speed, 128KB L1 cache and memory bandwidth. The biggest "feature" difference is the added support for 64-Bit computing with the Sempron 3400+. The 64-Bit ready Semprons are identifiable by the last two characters in the OPN. If the processor OPN ends with "BO" or "BX", this designates the processor as a 90nm, 754 Pin x86-64 Sempron Processor. With Commercial PC's utilizing a 64-Bit Sempron processor, manufacturers will clearly mark the machines as having a Sempron with AMD64 Technology.
A full review of the Sempron 3400+ can be found at HotHardware