The AMD Opteron 840 was a server/workstation processor with 1 core, launched in June 2003. It is part of the Opteron lineup, using the SledgeHammer (B3) architecture with Socket 940. Opteron 840 has 1 MB of L2 cache and operates at 1400 MHz. AMD is building the Opteron 840 on a 130 nm production process using 106 million transistors. The multiplier is locked on Opteron 840, which limits its overclocking capabilities.
With a TDP of 85 W, the Opteron 840 consumes a good deal of power, so decent cooling is needed. For communication with other components in the computer, Opteron 840 uses a PCI-Express Gen 2 connection. This processor lacks integrated graphics, you might need a graphics card.
Neither SSE3 nor SSE4 instruction sets are supported, which will lead to problems with games not starting.