Intel Core i5-8400H vs Intel Core i5-7287U

Intel Core i5-8400H

The Intel Core i5-8400H is a high-end processor for laptops with four cores based on the Coffee Lake architecture and will be announced early 2018. The processor clocks at between 2.5 and 4.2 GHz (4.1 with 4 cores) and can execute up to eight threads simultaneously thanks to Hyper-Threading. According to Intel, the CPU is manufactured in an improved 14nm (14nm++) process.

The Coffee Lake architecture is similar to Kaby Lake and differs only in the amount of cores (now six cores for the high end versions) and the improved 14nm process (14nm++ according to Intel).

Performance

The Intel Core i5-8400H should perform similar as the older Core i7-7920HQ (3.1 - 4.1 GHz). The faster Coffee Lake CPUs, like the Core i7-8750H offers two additional cores and is therefore up to 50% faster in multithreaded benchmarks. Still, the performance of the i5-8400H should be sufficient for even demanding applications and games.

Graphics

The integrated Intel UHD Graphics 630 iGPU is supposed to offer a slightly higher performance as its clock rate has been increased by 50 MHz (rumored). The architecture is identical to that of the Intel HD Graphics 630. We do expect a performance improvement, but as a low-end solution it will probably only display current games smoothly at reduced details - if at all.

Power Consumption

Intel specifies the TDP with 45 watts and therefore the i5 is only suited for big laptops with good cooling solutions. Using cTDP-down, the CPU can also be configured to 35 Watt resulting in a reduced performance.

Intel Core i5-7287U

The Intel Core i5-7287U is a fast dual-core SoC for notebooks based on the Kaby Lake architecture and was announced in January 2017. The CPU has two processor cores clocked at 3.3-3.7 GHz (two cores also up to 3.7 GHz). The processor can execute up to four threads simultaneously thanks to Hyper Threading. It is also equipped with an Intel Iris Plus Graphics 650 GPU with 64 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.

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 of the 28-Watt CPU should be on par with the Core i7-7560U (2.4-3.8 GHz, also 64 MB eDRAM, 15 Watts), where the Turbo Boost is usually shorter compared to the 7287U due to the lower TDP. This means the i5 is still one of the faster dual-core processors and should be sufficient for most scenarios. Some games might still require a real quad-core processor and therefore nit run perfectly on the dual-core processor, despite Hyper Threading.

Graphics

The integrated Intel Iris Plus 650 Graphics is the GT3e model of the Kaby Lake GPU (Intel Gen. 9.5). It has 48 Execution Units running at 300-1100 MHz and the performance is comparable to a GeForce 920MX thanks to fast eDRAM cache. However, there aren't any significant improvements compared to the old Iris Pro 550, 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 28 Watts, which can be reduced to 23 Watts (cTDP Down) depending on the usage scenario. The TDP is pretty high compared to the common 15-Watt TDP for dual-core processors, but allows a better utilization of CPU and GPU Turbo.