Core i7-3940XM vs Core i7-9700K

The Core i7-3940XM packs 4 cores / 8 threads, while the Core i7-9700K offers 8 cores / 8 threads — the Core i7-9700K has 4 more cores. Boost clocks reach 3.9 GHz on the Core i7-3940XM versus 4.9 GHz on the Core i7-9700K — a 22.7% clock advantage for the Core i7-9700K (base: 3 GHz vs 3.6 GHz). The Core i7-3940XM uses the Ivy Bridge (2012−2013) architecture (22 nm), while the Core i7-9700K uses Coffee Lake-R (2018−2019) (14 nm). In PassMark, the Core i7-3940XM scores 5,957 against the Core i7-9700K's 14,397 — a 82.9% lead for the Core i7-9700K. L3 cache: 8 MB (total) on the Core i7-3940XM vs 12 MB (total) on the Core i7-9700K.

The Core i7-3940XM uses the PGA988 socket (PCIe 3.0), while the Core i7-9700K uses LGA1151 (PCIe 3.0) — making them incompatible on the same motherboard. Maximum memory speed reaches DDR3-1600 on the Core i7-3940XM versus DDR4-2666 on the Core i7-9700K — the Core i7-9700K supports 28.6% faster memory, which can translate to measurable gains in memory-sensitive workloads. The Core i7-9700K 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. Both provide 16 PCIe lanes. Chipset compatibility: HM75,HM76,HM77,QM77,QS77 (Core i7-3940XM) and Intel 300 series (Core i7-9700K).

Both processors feature an unlocked multiplier for overclocking. Virtualization support: VT-x, VT-d, EPT (Core i7-3940XM) vs VT-x, VT-d (Core i7-9700K). Both include integrated graphics — HD Graphics 4000 (Core i7-3940XM) and UHD Graphics 630 (Core i7-9700K) — useful as a fallback for troubleshooting or display output without a dedicated GPU. Primary use case: Core i7-3940XM targets Extreme Performance Laptop, Core i7-9700K targets Desktop. Direct competitor: Core i7-3940XM rivals A10-5750M.