Intel Core i5-1155G7 vs Intel Core i3-8109U

The Intel Core i3-8109U is a dual-core SoC for notebooks based on the Coffee Lake architecture and was announced in April 2018. Compared to its predecessor Core i3-7167U, the CPU now supports Turbo boost with up to 3.6 GHz. Thanks to Hyperthreading the CPU can execute up to 4 threads simultaneously. It is also equipped with an Intel Iris Plus Graphics 655 GPU with 128 MB eDRAM (but with 300 - 1050 MHz it is the slowest Iris Plus), 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 (3rd generation) with FinFET transistors.

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 Turbo Boost, the processor performance should be a bit above the old Core i7-7500U (max. 3.5 GHz, 15 Watt). Therefore the Core i3-8109U should be fine for most applications. Some games however already need four real cores for optimal performance (paired with a dedicated GPU e.g.).

Graphics

The integrated Intel Iris Plus 655 Graphics is the GT3e model of the Kaby 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 (14nm++, 3rd generation of 14nm) 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 quad-core processors, but allows a better utilization of CPU and GPU Turbo.