Intel Core i5-1245U vs Intel Core i7-3840QM

Intel Core i5-1245U

The Intel Core i5-1245U is a mid-range mobile CPU for thin and light laptops based on the Alder Lake architecture. It was announced in early 2022 and offers 2 performance cores (P-cores, Golden Cove architecture) and 8 efficient cores (E-cores, Gracemont architecture). The P-cores support Hyper-Threading leading to 12 supported threads when combined with the E-cores. The clock rate ranges from 1.6 to 4.4 GHz on the performance cluster and 1.2 to 3.3 GHz on the efficient cluster. The performance of the E-cores should be similar to old Skylake cores (compare to the Core i7-6700HQ). All cores can use up to 12 MB L3 cache. Compared to the i7-1265U (fastest U-series CPU at launch), the 1245U offers lower clock speeds, a slower iGPU, but the full "Enterprise" vPro management features. Compared to the P-series (28W) or H-series (45W), the 15W TDP may limit the sustained performance.

Performance

Thanks to the 10 cores, the multi-threaded performance should be clearly faster than the older quad-core Tiger Lake CPUs with 15 Watt (like the Intel Core i7-1160G7). The sustained performance will be limited by the TDP setting and thermals and therefore only short term loads. Thanks to the architectural improvements of the big Golden Cove cores, the single thread performance should be better than similar clocked Tiger Lake CPUs.

Features

The integrated memory controller supports various memory types up to DDR5-4800, DDR4-3200, LPDDR5-5200, and LPDDR4x-4267. The Thread Director (in hardware) can support the operating system to decide which thread to use on the performance or efficient cores for the best performance. For AI tasks, the CPU also integrates GNA 3.0 and DL Boost (via AVX2). Quick Sync in version 8 is the same as in the Rocket Lake CPUs and supports MPEG-2, AVC, VC-1 decode, JPEG, VP8 decode, VP9, HEVC, and AV1 decode in hardware. The CPU only supports PCIe 4.0 (x8 for a GPU and two x4 for SSDs).

The integrated graphics adapter is based on the Xe-architecture and offers 80 of the 96 EUs (Execution Units) operating at up to 1.2 GHz.

The CPU is rated at 15 W base power (TDP, PL1) and 55 W max. Turbo power (PL2) and the whole SoC is manufactured on a 10nm process at Intel, which is known as Intel 7.

Intel Core i7-3840QM

The Intel Core i7-3840QM is a fast quad-core processor for laptops based on the Ivy Bridge architecture and successor of the i7-3820QM. Due to Hyperthreading, the four cores can handle up to eight threads in parallel leading to better utilization of the CPU. Each core offers a base speed of 2.8 GHz but can dynamically increase clock rates with Turbo Boost up to 3.6 GHz (for 4 active cores), 3.7 GHz (for 2 active cores) and 3.8 GHz (for 1 active core). Furthermore, the CPU offers 8 MB Last Level 3 Cache.

Ivy Bridge is an enhanced die shrink of the Sandy Bridge architecture with improvements on both GPU and CPU performance. The CPUs are produced in 22nm (versus 32nm Sandy Bridge CPUs) and are the first to introduce 3D transistors for increased energy efficiency when compared to similarly clocked Sandy Bridge processors. Other new features are integrated PCI Express 3.0 and  DDR3(L)-1600 support.

The performance of the Core i7-3840QM should be slightly above a similarly clocked Sandy Bridge processor due to slight architectural improvements. Overall, performance should be similar to the Core i7-3920XM.

The integrated Intel HD Graphics 4000 offers 16 Execution Units (EUs) clocked at 650 MHz up to 1300 MHz with Turbo Boost, making it one of the faster variants.

As with most quad-core Ivy Bridge models, the Core i7-3840QM is specified at a TDP of 45 Watts including graphics card and memory controller. Therefore, the CPU is well-suited for laptops 15-inches or greater.