Intel Core i3-7100U vs AMD A9-9420

Intel Core i3-7100U

The Intel Core i3-7100U is a dual-core processor of the Kaby Lake architecture. It offers two CPU cores clocked at 2.4 GHz (without Turbo Boost) and integrates HyperThreading to work with up to 4 threads at once. The architectural differences are rather small compared to the Skylake generation, therefore the performance per MHz should be very similar. The SoC includes a dual channel DDR4 memory controller and Intel HD Graphics 620 graphics card (clocked at 300 - 1000 MHz). It is manufactured in an improved 14nm FinFET process at Intel. Compare to the old Skylake Core i3-6100U, the i3-7100U offers a 100 MHz improved clock speed.

 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.

AMD A9-9420

The AMD A9-9420 is an entry-level chip from the Stoney-Ridge APU series for notebooks (7th APU generation), which was announced mid 2016. At its launch, the A9-9420 is the fastest Stoney Ridge processor (dual-core version of Bristol Ridge) and takes over that place from the A9-9410 (-100 MHz CPU clock). It integrates two CPU cores (one Excavator module with 2 integer and on FP unit) clocked between 3 - 3.6 GHz. It also includes a Radeon R5 GPU with 192 shaders at 800 MHz as well as a single-channel DDR4-2133 memory controller, H.265 video engine and chipset with all I/O ports.

Architecture

Stoney Ridge is the successor of the Carrizo architecture and the design is almost identical. Thanks to optimized manufacturing processes and more aggressive Boost behavior, however, the clocks are a bit higher at the same power consumption. The memory controller now also supports DDR4-RAM, in this case up to 2133 MHz. Stoney Ridge is the designation for the smaller dual-core and single-core chip, while Bristol Ridge is the bigger quad-core chip with dual-channel memory controller. More technical details are available in the following articles:

• AMD's Bristol Ridge and Stoney Ridge Architecture
• AMD: Bristol Ridge APUs announced

Performance

Thanks to the high maximum clock of up to 3.6 GHz, the single-core performance should be pretty good. The multi-core performance on the other hand is much lower compared to the Bristol Ridge models. Compared to older Carrizo-L/Beema quad-cores, the APU should still perform pretty well. The level of performance should be similar to a Core-m3 and therefore also be sufficient for more demanding applications.

The TDP can be configured between 10-25 Watts, so there can be big performance differences under sustained workloads.

Graphics Card

The integrated Radeon R5 (Stoney Ridge) GPU has 192 active shader units (3 compute cores) clocked at up to 800 MHz. More details about the GPU are available in the linked articles above. 

Power Consumption

AMD specifies the TDP of the A9-9420 with 15 Watts, but it can be configured between 10-25 Watts. This means the CPU is a good choice for thin and light notebooks, but also 15-inch devices with better cooling capabilities.