Xeon E5420

The Xeon E5420 is a 4-core / 4-thread processor based on the Harpertown (2007−2008) architecture, manufactured on a 45 nm process node. It reaches a maximum boost clock of 2.5 GHz from a base frequency of 2.5 GHz— higher boost clocks directly translate to better single-threaded performance and responsiveness in gaming. With a massive 12 MB L2 Cache L3 cache (3D V-Cache technology), this processor has a significant gaming advantage — the large cache drastically reduces memory latency in game engines., plus 6 MB (total) of L2 cache and 64 kB (per core) of L1 cache per core. In the PassMark benchmark (a comprehensive multi-threaded test), it scores 2,044, placing it in the Entry Level performance tier as a Legacy generation product. Geekbench 6 single-core (the most relevant metric for gaming FPS) records 314, while multi-core reaches 881.

The Xeon E5420 fits into the LGA771 socket and supports PCIe 2.0 with 32 total PCIe lanes for expansion cards and storage. It supports DDR2, DDR3 Depends on motherboard memory at speeds up to DDR2-667 (faster RAM improves bandwidth-sensitive workloads), with a maximum capacity of 32 GB across 4 channels (dual-channel doubles bandwidth). It supports ECC memory, providing error-correcting capabilities — essential for mission-critical workloads and servers.

Virtualization: Yes — enables running virtual machines efficiently (important for development and server workloads).

The Xeon E5420 has a rated TDP (Thermal Design Power) of 80 Watt — this indicates the amount of heat generated under sustained load and determines what cooling solution is needed. No stock cooler is included — you will need to purchase an aftermarket cooler separately.

At an average price of $6,500 (MSRP: $7214). Performance ranking position: #2564 out of all indexed processors.