AMD A9-9420 vs Intel Core i7-7700K

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.

Intel Core i7-7700K

The Intel Core i7-7700K is a fast quad-core processor for desktops based on the Kaby Lake architecture and was announced in January 2017. It is the top model of the consumer Kaby-Lake-H series at the time of the announcement. Besides four cores including Hyper-Threading (8 threads) support running at 4.2 - 4.5 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

Thanks to the 200 (base) and 300 MHz (Boost) higher clock speed, respectively, the i7-7700K is a few percent faster than the old Skylake Core i7-6700K that offers the same per-MHz performance. Therefore, it is a very fast quad-core CPU that offers sufficient performance for all tasks.

Graphics

The integrated Intel HD Graphics 630 has 24 Execution Units (similar to previous HD Graphics 530) running at 350 - 1150 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 slightly. Intel still specifies the TDP with 91 Watts, which is a lot more than the 45 Watts of the mobile Kaby-Lake-H CPUs.