The AMD Phenom II X2 B55 was a desktop processor with 2 cores, launched in October 2009. It is part of the Phenom II X2 lineup, using the Callisto architecture with Socket AM3. Phenom II X2 B55 has 6 MB of L3 cache and operates at 3 GHz. AMD is making the Phenom II X2 B55 on a 45 nm production node using 758 million transistors. The silicon die of the chip is not fabricated at AMD, but at the foundry of GlobalFoundries. The multiplier is locked on Phenom II X2 B55, which limits its overclocking potential.
With a TDP of 80 W, the Phenom II X2 B55 consumes a good deal of power, so decent cooling is needed. AMD's processor supports DDR2 and DDR3 memory with a dual-channel interface. The highest officially supported memory speed is 1333 MT/s, but with overclocking (and the right memory modules) you can go even higher. ECC memory is supported, too, which is an important capability for mission-critical systems, to avoid data corruption. For communication with other components in the machine, Phenom II X2 B55 uses a PCI-Express Gen 2 connection. Although the processor doesn't come with integrated graphics, certain motherboards with compatible chipsets can provide this capability.
Hardware virtualization is available on the Phenom II X2 B55, which greatly improves virtual machine performance.