Core i5-12400F vs Core i5-1240U

The Core i5-12400F packs 6 cores / 12 threads, while the Core i5-1240U offers 10 cores / 12 threads — the Core i5-1240U has 4 more cores. Boost clocks reach 4.4 GHz on the Core i5-12400F versus 4.4 GHz on the Core i5-1240U — identical boost frequencies (base: 2.5 GHz vs 1.1 GHz). The Core i5-12400F uses the Alder Lake-S (2022) architecture (Intel 7 nm), while the Core i5-1240U uses Alder Lake-U (2022) (Intel 7 nm). In PassMark, the Core i5-12400F scores 19,532 against the Core i5-1240U's 13,387 — a 37.3% lead for the Core i5-12400F. Geekbench 6 single-core — the metric most relevant to gaming — records 1,700 vs 1,650, a 3% lead for the Core i5-12400F that directly translates to higher frame rates. L3 cache: 18 MB (total) on the Core i5-12400F vs 12 MB (total) on the Core i5-1240U.

The Core i5-12400F uses the LGA1700 socket (PCIe 3.0), while the Core i5-1240U uses FCBGA1781 (PCIe 5.0) — making them incompatible on the same motherboard. Both support up to DDR5-4800, DDR4-3200 memory speed. The Core i5-12400F supports up to 128 GB of RAM compared to 64 GB — 66.7% more capacity for professional workloads. Both feature 2-channel memory with ECC support. PCIe lanes: 20 (Core i5-12400F) vs 14 (Core i5-1240U) — the Core i5-12400F offers 6 more lanes for additional GPUs or NVMe drives.

Both support VT-x, VT-d, EPT virtualization. The Core i5-1240U includes integrated graphics (Iris Xe Graphics 80EU), while the Core i5-12400F requires a dedicated GPU. Primary use case: Core i5-12400F targets Gaming Performance/Value, Core i5-1240U targets Thin & Light Laptop. Direct competitor: Core i5-12400F rivals Ryzen 5 5600; Core i5-1240U rivals Ryzen 5 5600U.