Intel Core i7-7500U vs Intel Core i7-3615QM vs Intel Core i7-3940XM

Intel Core i7-7500U

The Intel Core i7-7500U is a dual-core processor of the Kaby Lake architecture. It offers two CPU cores clocked at 2.7 - 3.5 GHz and integrates HyperThreading to work with up to 4 threads at once. The architectural differences are rather small compared to the Skylake generation, therefore the performance per MHz is very similar. The SoC includes a dual channel DDR4 memory controller and Intel HD Graphics 620 graphics card (clocked at 300 - 1050 MHz). It is manufactured in an improved 14nm FinFET process (14nm+) at Intel. Compared to the old Skylake Core i7-6500U (2.5 - 3.1 GHz), the i7-7500U clock speed is up to 400 MHz higher.

Intel Core i7-3615QM

The Intel Core i7-3615QM is a fast quad-core processor for laptops based on the Ivy Bridge architecture. 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 2.3 GHz but can dynamically increase clock rates with Turbo Boost up to 3.1 GHz (for 4 active cores), 3.2 GHz (for 2 active cores) and 3.3 GHz (for 1 active core).

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 i7-3615QM is slightly above a similarly clocked Sandy Bridge processor due to the architectural improvements. As a result, overall performance is similar to the former fastest model, the Core i7-2920XM.

The integrated Intel HD Graphics 4000 offers 16 Execution Units (EUs) clocked at 650 MHz up to 1200 MHz with Turbo Boost, making it one of the faster variants.

As with most quad-core Ivy Bridge models, the Core i7-3615QM 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.

Intel Core i7-3940XM

The Intel Core i7-3940XM is the fastest quad-core processor for laptops (at the time of introduction in September 2012) an successor of the i7-3920XM. 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 3.0 GHz but can dynamically increase clock rates with Turbo Boost up to 3.7 GHz (for 4 active cores), 3.8 GHz (for 2 active cores) and 3.9 GHz (for 1 active core). Furthermore, the Extreme CPUs offer an unlocked multiplicator for easy overclocking.

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 i7-3940XM should be slightly above a similarly clocked Sandy Bridge processor due to slight architectural improvements. Because of the higher clock speed, the former champion Core i7-3920XM should be outperformed by about 3%.

The integrated Intel HD Graphics 4000 offers 16 Execution Units (EUs) clocked at 650 MHz up to 1350 MHz with Turbo Boost, making it the fastest variant.

The XM CPUs are rated at a TDP of 55 Watts including graphics card and memory controller and therefore 10 Watt higher than the other quad-core models.  Therefore, the CPU is well-suited for laptops 17-inches or greater.