AMD Admits Oversight: Zen 4c Specs Emerge, Website Update Incoming

In April this year, AMD launched the Ryzen Z1 series APU designed for handheld gaming devices. The lower-end Ryzen Z1 employs the Phoenix2 chip, a hybrid architecture combining Zen 4 and Zen 4c, introducing the Zen 4c architecture cores into the consumer market for the first time.

AMD has long refrained from detailing specific information about the Zen 4c, with its official website lacking specification pages and marketing materials offering no explanations. According to a report by TomsHardware, after communication with AMD, more information about the Zen 4c architecture cores has been revealed, and AMD has promised to update its website content to more prominently feature this information in its materials.

Unlike Intel’s “big.LITTLE” core philosophy, the Zen 4c architecture shares the same ISA as Zen 4. Essentially, it is a low-power, streamlined version of the Zen 4 core, offering the same IPC but with a higher energy efficiency ratio. The physical size of a Zen 4c core is significantly smaller than that of a Zen 4 core. However, due to the lower frequency of Zen 4c cores, their peak performance is less than the standard Zen 4 cores.

There are currently five consumer-grade chips on the market that utilize Zen 4c cores. However, AMD has not highlighted the presence of Zen 4c cores on its main specification page. Users need to navigate to a secondary “complete specifications” page, and even there, the information is somewhat ambiguous. Many users are unclear about what “2x Zen 4, 4x Zen 4c” specifically denotes. AMD’s new Ryzen 5 8540U and Ryzen 3 8440U both feature Zen 4c cores, but this is not mentioned in their marketing materials. The impact is more significant for the Ryzen 3 8440U, as its configuration of 1x Zen 4 + 3x Zen 4c results in a noticeable performance differential.

In contrast, Intel informs users about the presence and frequencies of E-Cores on their specification pages and marketing materials. As for AMD, users are currently unaware of the frequencies of Zen 4c cores. AMD has indicated that it will soon disclose the base and maximum frequencies of the Zen 4c cores. AMD explains that this delay in disclosure is due to the need to review content and consider how to present it, as their hybrid architecture strategy differs from Intel’s. Furthermore, there are significant performance positioning differences between Zen 4c cores and E-Cores, making a direct comparison between the two impractical.