AMD A4-9120C vs Intel Core i7-7700T

AMD A4-9120C

The AMD A4-9120C is an entry-level chip from the Stoney-Ridge APU series for Chromebooks and entry level laptops (7th APU generation from 2016), which was announced early 2019. It is based on the similar named A4-9120 from 2016 but with a reduced TDP (6 versus 15 Watt) and reduced clock speeds of 1.6 - 2.4 GHz (compared to 2.2 - 2.5 GHz). Both CPUs integrate two CPU cores (one Excavator module with 2 integer and on FP unit).

It also includes a Radeon R4 GPU with 192 shaders at 600 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

Because of the significantly lower clock speed, the A4-9120C should be noticeably slower than the old A4-9120. AMD compares the A4-9120C with the Celeron N3350 in ChromeOS and sees a significant performance advantage for the A4. The efficiency however should be clearly worse as the A4-9120C is still manufactured in 28nm.

Power Consumption

AMD specifies the TDP of the A4-9120C with 6 Watts which should enable thin and light Chromebooks (even fanless).

Intel Core i7-7700T

The Intel Core i7-7700T 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 35 Watt models and significantly slower than the similar named Core i7-7700K. The four Skylake based CPU cores are clocked from 2.9 - 3.8 GHz and support HyperThreading / SMT (8 threads).

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 i7-7700T is slightly faster than the Core i5-7600K with sufficient cooling and TDP settings. Therefore, the CPU is fine to handle even demanding tasks and apps.

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.