Intel Core i5-7300HQ vs Intel Core i5-8257U vs Intel Core i7-8559U

Intel Core i5-7300HQ

The Intel Core i5-7300HQ is a quad-core processor for notebooks based on the Kaby Lake architecture and was announced in January 2017. Compared to the faster Core i7 models, the Core i5 does not support Hyper Threading and has lower clocks. The CPU cores run at 2.5 - 3.5 GHz (4 cores up to 3.1, 2 cores up to 3.3 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

The performance should be quite similar to the old Core i5-6440HQ (2.6 - 3.5 GHz, Skylake) that offers the same per-MHz performance and only 100 MHz higher core speed. The performance is therefore sufficient even for demanding tasks.

Graphics

The integrated Intel HD Graphics 630 has 24 Execution Units (similar to previous HD Graphics 530) running at 350 - 1000 MHz (i7 models up to 1100). 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 i5-8257U

The Intel Core i5-8257U is a quad-core SoC for notebooks based on the Coffee Lake architecture that was announced in the new entry level MacBook Pro 13 in mid 2019. Compared to its predecessor, the CPU is now a quad-core with Hyperthreading support for the execution of up to 8 threads simultaneously. The base frequency is only 1.4 GHz, but the Turbo goes all the way up to 3.9 GHz. It is also equipped with an Intel Iris Plus Graphics 645 GPU with 128 MB eDRAM, a dual-channel memory controller (DDR4) as well as VP9 and H.265 video decoding as well as encoding. The chip is still manufactured in a 14nm process with FinFET transistors.

Compared to faster Core i7-8557U model with eDRAM and 15 Watts, the i5-8257U only features 6 MB smart cache and the slowest clock of the Iris Plus GPU.

Architecture

Intel basically uses the same micro architecture compared to Kaby Lake, 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

Thanks to the relative high Turbo Boost clock, the single thread performance should be very good, but still behind the faster i7 model. The short burst all core performance is clearly better compared to the old dual core predecessors thanks to the additional cores. In sustained workloads, the performance is usually limited by the TDP and cooling. In these workloads the difference to the Core i7 should be also smaller.

Graphics

The integrated Intel Iris Plus 645 Graphics is the GT3e model of the Coffee Lake GPU (Intel Gen. 9.5). It has 48 Execution Units running at 300-1050 MHz and the performance is comparable to a GeForce 930M or 940MX thanks to fast eDRAM cache. However, there aren't any significant improvements compared to the old Iris Plus 650, so modern games can often not be played smoothly or only at the lowest or medium settings, respectively.

Contrary to Skylake, Kaby lake now also supports H.265/HEVC Main 10 with a 10-bit color depth as well as Google's VP9 codec. The dual-core Kaby Lake processors 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 specifies the TDP with 15 Watts and therefore suited for thin and light laptops.

Intel Core i7-8559U