Core i5-520UM vs Xeon E5603

The Core i5-520UM packs 2 cores / 4 threads, while the Xeon E5603 offers 4 cores / 4 threads — the Xeon E5603 has 2 more cores. Boost clocks reach 1.87 GHz on the Core i5-520UM versus 1.6 GHz on the Xeon E5603 — a 15.6% clock advantage for the Core i5-520UM (base: 1.07 GHz vs 1.6 GHz). The Core i5-520UM uses the Arrandale (2010−2011) architecture (32 nm), while the Xeon E5603 uses Westmere-EP (2010−2011) (32 nm). In PassMark, the Core i5-520UM scores 1,943 against the Xeon E5603's 1,935 — a 0.4% lead for the Core i5-520UM. L3 cache: 3 MB on the Core i5-520UM vs 4 MB (total) on the Xeon E5603.

The Core i5-520UM uses the BGA1288 socket (PCIe 2.0), while the Xeon E5603 uses LGA1366 (PCIe 2.0) — making them incompatible on the same motherboard. Maximum memory speed reaches 800 on the Core i5-520UM versus DDR3-1066 on the Xeon E5603 — the Core i5-520UM supports 198.5% faster memory, which can translate to measurable gains in memory-sensitive workloads. The Xeon E5603 supports up to 288 GB of RAM compared to 8 — 189.2% more capacity for professional workloads. Memory channels: 2 (Core i5-520UM) vs 3 (Xeon E5603). PCIe lanes: 16 (Core i5-520UM) vs 32 (Xeon E5603) — the Xeon E5603 offers 16 more lanes for additional GPUs or NVMe drives.

Neither processor supports overclocking. Virtualization support: true (Core i5-520UM) vs VT-x, VT-d (Xeon E5603). The Core i5-520UM includes integrated graphics (Intel HD Graphics (Ironlake)), while the Xeon E5603 requires a dedicated GPU. Primary use case: Xeon E5603 targets Server. Direct competitor: Core i5-520UM rivals Core 2 Duo SU9400.