Intel Core i7-3520M vs Intel Core i7-7600U

Intel Core i7-3520M

The Intel Core i7-3520M is the fastest dual-core processor for laptops based on the Ivy Bridge architecture at the time of introduction in Q2 2012. Due to Hyperthreading, the two cores can handle up to four threads in parallel leading to better utilization of the CPU. Each core offers a base speed of 2.9 GHz but can dynamically increase clock rates with Turbo Boost up to 3.4 GHz (for 2 active cores) and 3.6 GHz (for 1 active core). As its Sandy-Bridge-based predecessor Core i7-2640M, it offers a 4 MB L3-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 i7-3520M is slightly above a similarly clocked Sandy Bridge processor due to the architectural improvements. As a result, overall performance is about 5 - 10 % above the old i7-2640M (see benchmarks below).

The integrated Intel HD Graphics 4000 offers 16 Execution Units (EUs) clocked at 650 MHz up to 1250 MHz with Turbo Boost, making it one of the fastest variants.

Just like most other Ivy Bridge dual-cores, the i7-3520M is rated at a TDP of 35 W. Therefore, even smaller laptops can use the Core i7.

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.