AMD is allegedly working on its first hybrid core processor, popularly known as big.LITTLE in the mobile industry. Codenamed Phoenix 2, this SKU will leverage a 2+4 design with two P-cores and four E-cores. The former refers to the standard Zen 4 cores used on the Ryzen 7000 processors, while the latter is internally known as the “classic dense core”.
Phoenix has a variant that use "big-LITTLE" like core design, which contains a CCX with 2+4 design with standard Zen 4 and a dense-optimized variant of Zen 4 (Zen 4c? or Zen 4 Dense).
Below figure is tested on this PHX variant using R23 multi-core loading and can see huge different frequency the cores are running on. The standard PHX doesnt use “big-LITTLE” design or AMD call it “classic dense” core.
Originally tweeted by Xino (@xinoassassin1) on March 26, 2023.
Xino on Twitter has shared the alleged frequency graph of the Phoenix 2 hybrid processor running Cinebench R23. In this scenario, the efficiency cores maintain an average clock of 2.7-2.8GHz with a spike of 3.5GHz near the end of the benchmark. The performance cores average 4.7-4.8GHz with a peak of nearly 5GHz.
Cinebench R23 is a heavily threaded workload that tests the limits of a processor. The power consumption generally hits the upper limit in this benchmark. It’ll be more interesting to see how the small cores improve the chip’s efficiency in lightly threaded workloads.
At the time of writing, it is unclear whether AMD will leverage the stripped-down Zen 4c core or simply a tweaked or downclocked Zen 4 core.