AMD A4-9120C vs AMD A9-9420e

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).

AMD A9-9420e

The AMD A9-9420e is an entry-level chip from the Stoney-Ridge APU series for notebooks (7th APU generation). It was first found in the Dell Inspiron 3000 with passive cooling and 4 GB DDR4 RAM. The performance in that device was way below the normal A9-9420 as the clock speed only reached up to 2,5 GHz. It also includes a Radeon R5 GPU with 192 shaders 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

Power Consumption

AMD specifies the TDP of the A9-9420 between 10-25 Watts, but the passively cooled A9-9420e should be positioned lower than 9 Watt.