Source: AMD
For a while, it’s been rumored AMD is planning to launch an APU that uses a combination of Zen 4 and Zen 4c cores the same way Intel uses P-cores and E-cores in its CPUs, and AMD has even confirmed it would eventually launch such a chip. Earlier this month, a leaked photo of an as-of-yet undisclosed APU (codenamed Phoenix 2) indicated that this hybrid chip would be coming sooner rather than later. According to various leakers, this Phoenix 2 chip would have two Zen 4 cores and four Zen 4c cores for six total and would see use in the Ryzen 3 7440U.
Ever the rumor skeptic, I wanted to know whether the rumor was true or not, so I asked AMD, and to my surprise, AMD confirmed that it did in fact have a six-core APU, and it would be used for the 7440U. While AMD stopped short of confirming that the underlying design used a hybrid architecture, the details line up so perfectly with the rumor that it’s all but certain.
What we know about AMD’s six-core APU
In my correspondence with AMD, several key details about this small APU (presumably Phoenix 2) were confirmed, and it’s not just a simple hybrid version of the larger 8-core Phoenix design used in the higher-end models.
| Phoenix | Phoenix 2 | |
|---|---|---|
| CPU Cores | 8 | 6 |
| GPU Cores | 12 | 4 |
| Ryzen AI | Yes | No |
| Die Size | 178mm2 | 137mm2 |
While AMD did not mention that this smaller APU would be a hybrid design, it’s highly likely that it is for architectural reasons. AMD has never made a Zen CPU with just six cores, and there are good technical reasons why that I won’t get too deep into. All Zen chips up to today have contained either 2, 4, or 8 cores. What Phoenix 2 essentially does is combine a dual-core Zen 4 CPU and a quad-core Zen 4c CPU into the same chip, much like how APUs contain both CPU and GPU cores. AMD’s confirmation of a six-core APU is the smoking gun.
The original rumor suggested that Phoenix 2 would feature in the Ryzen 3 7440U and Ryzen 5 7540U, and since the 7540U is advertised as not having Ryzen AI and 4 GPU cores, this is plausible. However, I asked AMD to confirm whether the Ryzen 5 7540U used this new APU, and I was told it’s “just the 7440U for now”. That implies that while Phoenix 2 could be used for the 7540U, AMD is choosing not to in the near future.
So, does this mean the 7440U is AMD’s first hybrid processor? Well, maybe not. Rumors have indicated that both the 8-core Phoenix and 6-core Phoenix 2 chips will be used in the 7440U, a dual-sourcing strategy that would ensure plenty of supply for these low-end APUs. Because the regular Phoenix chips aren’t hybrid, we would have to assume that the 7440U and the 7540U won’t take full advantage of the hybrid nature of the Phoenix 2 design. Additionally, it’s unclear how AMD plans on utilizing Zen 4 and 4c cores in a hybrid APU since unlike Intel’s P-cores and E-cores, Zen 4 and 4c are architecturally identical, though Zen 4c has a more limited frequency.
There’s still much we don’t know about Phoenix 2, such as when it will finally be available and when AMD will launch an APU that will take full advantage of the Phoenix 2 chip’s six cores and hybrid architecture. But since Phoenix 2 is actually out in the wild, it probably won’t be long before AMD starts talking about it.