Intel Core i3-6157U vs AMD A9-9420

Intel Core i3-6157U

The Intel Core i3-6157U is a dual-core SoC based on the Skylake architecture and has been launched in September 2015. The CPU can be found in medium-sized ultrabooks as well as normal notebooks. In addition to two CPU cores with Hyper-Threading clocked at 2.4 GHz (no Turbo Boost), the chip also integrates an Iris Graphics 550 GPU with 64 MB of eDRAM memory as well as a dual-channel DDR4-2133/DDR3L-1600 memory controller. The SoC is manufactured using a 14 nm process with FinFET transistors.

Architecture

Skylake replaces both Haswell and Broadwell and brings the same microarchitecture in every TDP class from 4.5 to 45 W. The extensive improvements of the Skylake design include increased out-of-order buffers, optimized prefetching and branch prediction as well as additional performance gains through Hyper-Threading. Overall, however, performance per clock has been increased by only 5 to 10 percent (compared to Haswell) respectively under 5 percent (compard to Broadwell), which is quite modest for a new architecture ("Tock").

Furthermore, the organisation of the eDRAM cache has been modified. Instead of acting like a victim cache, which has to be adressed via the L3/LLC, the eDRAM can now be adressed directly by programms just like the main memory. The size is still 128 MB for the quad-core models (4C + GT4e), while the dual-core chips (2C + GT3e) only offer 64 MB.

Performance

According to the specified clock rates and the improved architecture, the Core i3-6157U should perform similar to a Core i3-5157U (Broadwell, 15 W). Thus, the CPU has sufficient power for office and multimedia purposes as well as more demanding applications and multitasking.

Graphics

The integrated graphics unit called Iris Graphics 550 represents the "GT3e" version of the Skylake GPU (Intel Gen. 9). The 48 Execution Units, also called EUs, are clocked at 350 - 1000 MHz and offer (thanks to the fast eDRAM cache) a performance similar to a dedicated GeForce 930M. Games of 2015 can thus be played smoothly in low or medium settings. For more information about performance and features, check our page for the Iris Graphics 550.

Power Consumption

Specified at a TDP of 28 W (including CPU, GPU and memory controller), the CPU is best suited for medium-sized notebooks (13-inches and above). Optionally, the TDP can be lowered to 23 watts (cTDP down), reducing both heat dissipation and performance.

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.