Core i5-8265U vs Core i7-3840QM

Both the Core i5-8265U and Core i7-3840QM share an identical 4-core/8-thread configuration. Boost clocks reach 3.9 GHz on the Core i5-8265U versus 3.8 GHz on the Core i7-3840QM — a 2.6% clock advantage for the Core i5-8265U (base: 1.6 GHz vs 2.8 GHz). The Core i5-8265U uses the Whiskey Lake-U (2018−2019) architecture (14 nm), while the Core i7-3840QM uses Ivy Bridge (2012−2013) (22 nm). In PassMark, the Core i5-8265U scores 5,812 against the Core i7-3840QM's 5,871 — a 1% lead for the Core i7-3840QM. Geekbench 6 single-core — the metric most relevant to gaming — records 1,200 vs 676, a 55.9% lead for the Core i5-8265U that directly translates to higher frame rates. L3 cache: 6 MB (total) on the Core i5-8265U vs 8 MB (total) on the Core i7-3840QM.

The Core i5-8265U uses the FCBGA1528 socket (PCIe 3.0), while the Core i7-3840QM uses PGA988 (PCIe 3.0) — making them incompatible on the same motherboard. Maximum memory speed reaches DDR4-2400 on the Core i5-8265U versus DDR3-1600 on the Core i7-3840QM — the Core i5-8265U supports 28.6% faster memory, which can translate to measurable gains in memory-sensitive workloads. The Core i5-8265U supports up to 64 GB of RAM compared to 32 GB — 66.7% more capacity for professional workloads. Both feature 2-channel memory with ECC support. Both provide 16 PCIe lanes. Chipset compatibility: SoC (Core i5-8265U) and HM75,HM76,HM77,QM77,QS77 (Core i7-3840QM).

Neither processor supports overclocking. Both support VT-x, VT-d, EPT virtualization. Both include integrated graphics — Intel UHD Graphics 620 (Core i5-8265U) and HD Graphics 4000 (Core i7-3840QM) — useful as a fallback for troubleshooting or display output without a dedicated GPU. Primary use case: Core i5-8265U targets Mainstream Laptop, Core i7-3840QM targets Mobile Workstation. Direct competitor: Core i7-3840QM rivals A10-5750M.