The AMD Phenom II X4 840 was a desktop processor with 4 cores, launched in January 2011. It is part of the Phenom II X4 lineup, using the Propus architecture with Socket AM3. Phenom II X4 840 has 512 KB of L2 cache per core and operates at 3.2 GHz. AMD is building the Phenom II X4 840 on a 45 nm production process using 300 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 X4 840, which limits its overclocking capabilities. With a TDP of 95 W, the Phenom II X4 840 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 X4 840 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 X4 840, which greatly improves virtual machine performance.