Core i5-520UM vs Core i3-4158U

Both the Core i5-520UM and Core i3-4158U share an identical 2-core/4-thread configuration. Boost clocks reach 1.87 GHz on the Core i5-520UM versus 2 GHz on the Core i3-4158U — a 6.7% clock advantage for the Core i3-4158U (base: 1.07 GHz vs 2 GHz). The Core i5-520UM uses the Arrandale (2010−2011) architecture (32 nm), while the Core i3-4158U uses Haswell (2013−2015) (22 nm). In PassMark, the Core i5-520UM scores 1,943 against the Core i3-4158U's 1,921 — a 1.1% lead for the Core i5-520UM. L3 cache: 3 MB on the Core i5-520UM vs 3 MB (total) on the Core i3-4158U.

The Core i5-520UM uses the BGA1288 socket (PCIe 2.0), while the Core i3-4158U uses FCBGA1168 (PCIe 3.0) — making them incompatible on the same motherboard. Maximum memory speed reaches 800 on the Core i5-520UM versus DDR3L-1600 on the Core i3-4158U — the Core i5-520UM supports 198.5% faster memory, which can translate to measurable gains in memory-sensitive workloads. The Core i3-4158U supports up to 16 GB of RAM compared to 8 — 66.7% more capacity for professional workloads. Both feature 2-channel memory with ECC support. PCIe lanes: 16 (Core i5-520UM) vs 12 (Core i3-4158U) — the Core i5-520UM offers 4 more lanes for additional GPUs or NVMe drives. Chipset compatibility: HM55,HM57,QM57,QS57 (Core i5-520UM) and HM86,HM87 (Core i3-4158U).

Neither processor supports overclocking. Virtualization support: true (Core i5-520UM) vs VT-x / VT-d / EPT (Core i3-4158U). Both include integrated graphics — Intel HD Graphics (Ironlake) (Core i5-520UM) and Intel Iris Graphics 5100 (Core i3-4158U) — useful as a fallback for troubleshooting or display output without a dedicated GPU. Primary use case: Core i3-4158U targets Multimedia. Direct competitor: Core i5-520UM rivals Core 2 Duo SU9400.