In April this year, AMD released the Ryzen Z1 series APUs for mobile handheld gaming devices, in which the lower-positioned Ryzen Z1 uses the Zen 4 + Zen 4C hybrid architecture Phoenix2 chip, bringing the Zen 4C architecture core to the consumer market for the first time.
For a long time, AMD did not provide specific information about the ZEN 4C, the official website lacked a specs page, and the marketing materials did not explain. According to Tomshardware, after contacting and communicating with AMD, more information about the Zen 4C architecture kernel has been revealed to it, and it promises that the content will be more prominent in relevant materials after the content is updated. 
Unlike Intel's "big and small cores" idea, the Zen 4C architecture uses the same ISA as the Zen 4 architecture, which is essentially a low-power lite version of the Zen 4 architecture core, with the same IPC, a higher energy consumption ratio, and the size of the Zen 4C core is much smaller than the Zen 4 core. However, due to the lower frequency of the Zen 4C core, the peak performance provided is lower than that of the standard Zen 4 core.
At present, there are 5 consumer-grade chips on the market with Zen 4C cores, but AMD did not prompt the existence of Zen 4C cores on the main specifications page, to navigate to the second "full specifications" page, and the introduction is also ambiguous, many users are not clear about what "2X Zen 4, 4X Zen 4C" specifically represents. Both the AMD Ryzen 5 8540U and Ryzen 3 8440U are equipped with ZEN 4C cores, but this is not mentioned in the promotional materials. Among them, the Ryzen 3 8440U has a greater impact, because its combination is 1X Zen 4 + 3X Zen 4C, there will be a significant difference in performance.
In addition, Intel informs the existence of e-cores and how often they are on the specs page and promotional materials. On the other hand, AMD, users don't know the frequency of the ZEN4C core at all. AMD has informed that the base and maximum frequencies of the ZEN 4C core will be announced next. AMD explained that it needs to examine what is disclosed and consider how it is expressed, as its hybrid architecture strategy is different from Intel's, and the performance positioning of Zen 4C cores and e-cores is also very different, and the two cannot be simply compared.