Core i7-3840QM vs Core i5-12400F

The Core i7-3840QM packs 4 cores / 8 threads, while the Core i5-12400F offers 6 cores / 12 threads — the Core i5-12400F has 2 more cores. Boost clocks reach 3.8 GHz on the Core i7-3840QM versus 4.4 GHz on the Core i5-12400F — a 14.6% clock advantage for the Core i5-12400F (base: 2.8 GHz vs 2.5 GHz). The Core i7-3840QM uses the Ivy Bridge (2012−2013) architecture (22 nm), while the Core i5-12400F uses Alder Lake-S (2022) (Intel 7 nm). In PassMark, the Core i7-3840QM scores 5,871 against the Core i5-12400F's 19,532 — a 107.6% lead for the Core i5-12400F. Geekbench 6 single-core — the metric most relevant to gaming — records 676 vs 1,700, a 86.2% lead for the Core i5-12400F that directly translates to higher frame rates. L3 cache: 8 MB (total) on the Core i7-3840QM vs 18 MB (total) on the Core i5-12400F.

The Core i7-3840QM uses the PGA988 socket (PCIe 3.0), while the Core i5-12400F uses LGA1700 (PCIe 3.0) — making them incompatible on the same motherboard. Maximum memory speed reaches DDR3-1600 on the Core i7-3840QM versus DDR5-4800, DDR4-3200 on the Core i5-12400F — the Core i5-12400F supports 50% faster memory, which can translate to measurable gains in memory-sensitive workloads. The Core i5-12400F supports up to 128 GB of RAM compared to 32 GB — 120% more capacity for professional workloads. Both feature 2-channel memory with ECC support. PCIe lanes: 16 (Core i7-3840QM) vs 20 (Core i5-12400F) — the Core i5-12400F offers 4 more lanes for additional GPUs or NVMe drives. Chipset compatibility: HM75,HM76,HM77,QM77,QS77 (Core i7-3840QM) and H610,B660,H670,Z690,B760,H770,Z790 (Core i5-12400F).

Both support VT-x, VT-d, EPT virtualization. The Core i7-3840QM includes integrated graphics (HD Graphics 4000), while the Core i5-12400F requires a dedicated GPU. Primary use case: Core i7-3840QM targets Mobile Workstation, Core i5-12400F targets Gaming Performance/Value. Direct competitor: Core i7-3840QM rivals A10-5750M; Core i5-12400F rivals Ryzen 5 5600.