Intel Core i7-3517U vs Intel Core i7-7820HQ vs Intel Core i7-3720QM

Intel Core i7-3517U

The Intel Core i7-3517U is a fast ULV-processor for laptops based on the Ivy Bridge architecture released 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 1.9 GHz but can dynamically increase clock rates with Turbo Boost up to 2.8 GHz (for 2 active cores) and 3.0 GHz (for 1 active core). As its Sandy-Bridge-based predecessors, 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 i7-3517U is slightly above a similarly clocked Sandy Bridge processor due to the architectural improvements. Therefore, and because of the higher clock speed, the older Core i7-2677M is easily outperformed.

The integrated Intel HD Graphics 4000 offers 16 Execution Units (EUs) clocked at 350 MHz up to 1150 MHz with Turbo Boost, delivering a performance comparable with an AMD Radeon HD 6620G.

The ULV-CPUs are rated at a TDP of 17 W including graphics card and memory controller.  Therefore, the CPU is suited for small laptops and ultrabooks.

Intel Core i7-7820HQ

The Intel Core i7-7820HQ is a fast quad-core processor for notebooks based on the Kaby Lake architecture and was announced in January 2017. It is the second fastest model of the consumer series at the time of the announcement. Only the i7-7920HQ and Xeon E3-1535M v6 are faster. Besides four cores including Hyper-Threading support running at 2.9 - 3.9 GHz (4 cores up to 3.5 GHz, 2 cores up to 3.7 GHz), the processor is also equipped with the HD Graphics 630 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

Due to the higher clock speeds, the performance of the i7-7820HQ is slightly faster than the old Skylake top model Core i7-6920HQ (2.9 - 3.8 GHz). The performance is sufficient even for very demanding tasks and on par with powerful desktop quad-core processors.

Graphics

The integrated Intel HD Graphics 630 has 24 Execution Units (similar to previous HD Graphics 530) running at 350 - 1100 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 45 Watts, but it can also be reduced to 35 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 i7-3720QM

The Intel Core i7-3720QM is a fast high-end 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 2.6 GHz but can dynamically increase clock rates with Turbo Boost up to 3.4 GHz (for 4 active cores), 3.5 GHz (for 2 active cores) and 3.6 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 i7-3720QM is slightly above a similarly clocked Sandy Bridge processor due to slight architectural improvements. As a result, overall performance is higher than 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 1250 MHz with Turbo Boost, making it one of the faster variants.

As with most quad-core Ivy Bridge models, the Core i7-3720QM 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.