Intel Core i7-7600U vs Intel Core i7-4940MX vs Intel Core i7-4870HQ

Intel Core i7-7600U

The Intel Core i7-7600U is a fast dual-core processor for notebooks based on the Kaby Lake architecture and was announced in January 2017. It integrates 2 CPU cores with Hyper-Threading support clocked at 2.8 - 3.9 GHz (2 core Turbo also 3.9 GHz). Besides two cores, the processor is also equipped with the HD Graphics 620 GPU as well as a dual-channel memory controller (DDR3L-1600/DDR4-2400). It is manufactured in a 14nm process with FinFET transistors.

Architecture

Intel basically uses the same micro architecture compared to Skylake, so the per-MHz performance does not differ. The manufacturer only reworked the Speed Shift technology for faster dynamic adjustments of voltages and clocks, and the improved 14nm process allows much higher frequencies combined with better efficiency than before.

Performance

With 2.5 to 3.9 GHz, the Core i7-7600U clocks significantly higher than the old Core i7-6500U (2.5 - 3.1). That means, the i7-7600U is (at the time of announcement in beginning of 2017) the fastest dual core processor for laptops. The performance is sufficient for demanding tasks (except some games that may need four real cores).

Graphics

The integrated Intel HD Graphics 620 has 24 Execution Units (similar to previous HD Graphics 520) running at 300 - 1150 MHz. The performance depends a lot on the memory configuration; it should be comparable to a dedicated Nvidia GeForce 920M in combination with fast DDR4-2133 dual-channel memory.

Contrary to Skylake, Kaby Lake now supports hardware decoding for H.265/HEVC Main 10 with a 10-bit color depth as well as Google's VP9 codec. The dual-core Kaby Lake processors, which were announced in January, should also support HDCP 2.2.

Power Consumption

The chip is manufactured in an improved 14nm process with FinFET transistors, which improves the efficiency even further. Intel still specifies the TDP with 15 Watts, but it can also be reduced to 7.5 Watts by the notebook manufacturers (cTDP down). This will obviously affect the performance, because the Turbo Boost cannot be maintained for longer periods.

Intel Core i7-4940MX

The Intel Core i7-4940MX is a high-end quad-core processor for laptops and successor of the i7-4930MX. It is based on the Haswell architecture and was launched in Q1/2014. 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 3.1 GHz but can dynamically increase clock rates with Turbo Boost up to 3.8 GHz (for 4 active cores), 3.9 GHz (for 2 active cores) and 4.0 GHz (for 1 active core). Furthermore, the Extreme CPUs offer an unlocked multiplicator for easy overclocking.

Architecture

Haswell is the successor to the Ivy Bridge architecture with improvements on both GPU and CPU performance. The CPUs are produced in 22nm and offer an optimized branch prediction as well as additional execution ports, increasing the performance per clock by about 5 - 10 percent. Furthermore, new features like AVX2 and FMA should increase the performance in future applications.

Performance

Compared to the Core i7-4930MX, the 4940MX is clocked just 100 MHz higher and therefore only slightly faster. Overall, the performance is similar to the Desktop Core i7-4770K. Even extremly demanding software or multitasking will be handled easily.

Graphics

The integrated Intel HD Graphics 4600 offers 20 Execution Units (EUs) clocked at 400 MHz up to 1350 MHz with Turbo Boost, making it about 30 % faster than the HD 4000. This is slightly slower than the AMD Radeon HD 8650G, but similar to a dedicated GeForce GT 720M.

Power Consumption

The i7-4940MX is rated at a TDP of 57 W including graphics card, memory controller and VRMs.  Therefore, the CPU is only suited for laptops 17-inches or greater.

Intel Core i7-4870HQ