AMD Intros Zen 4C Powered Ryzen 7040 APU: Smaller Cores Open Room For Future Core Count Increases

AMD has finally introduced its brand new Ryzen 7040 APUs based on the Zen 4C cores which pave the way for future core count increases.

As we have seen with Threadripper 7000 options, AMD is now investing in the use of smaller cores for a diverse range of Ryzen APUs for the client segment. While the Ryzen 7040 APUs initially used the Zen 4 cores, the company has now introduced brand new options that adopt the Zen 4C cores for a more scalable design.

The AMD Zen 4C CCD which is codenamed "Dinoysus" has an overall -35.4% lower core area and almost every aspect of the CCD has been reduced by -35% to -45%.

So coming to the major changes between Zen 4 and Zen 4C on an architectural level, only the L3 cache per core has been reduced from 4 MB per core to 2 MB per core. The rest of the specs are entirely the same and that's a huge deal considering Zen 4C isn't a full-on different architecture from Intel's E-Core and P-Core variations.

The company has already stated that, unlike Intel's approach, the Zen 4 and Zen 4C cores use the same ISA and have the same IPC. Also unlike Intel's E-core implementation, the Zen 4C cores still come with SMT support and retain the same level of performance in gaming which ends up being a major issue with Intel's E-Cores since they lack the same IPC or clock speed advantage that the P-cores have. Another size-saving tactic is the dropout of the Ryzen AI unit (NPU) which isn't featured on the Phoenix 2 SKUs though future premium chips will retain the AI prowess of the NPU. It's the specific nature of the Ryzen 7040U and its target market (entry-level) that doesn't warranty the use of Ryzen AI.

Now coming to the SKUs, the AMD Zen 4C & Zen 4 hybrid chips, codenamed Phoenix 2, include the Ryzen 5 7545U and the Ryzen 3 7440U.

In terms of specifications, the AMD Ryzen 5 7545U offers two Zen 4 cores (4 threads) and 4 Zen 4C cores (8 threads) that makeup 6 cores and 12 threads, running at a base clock speed of 3.2 GHz & a boost clock of 4.9 GHz. The Ryzen 3 7440U also gets one Zen 4 core (2 threads) and 3 Zen 4C (6 threads) configuration that's clocked at a base frequency of 3.0 GHz & boost frequency of 4.7 GHz. Both chips retain 16 MB and 8 MB L3 cache counts.

Both chips have a TDP range of 15-30W and one significant detail is that they both come up with an AMD Radeon 740M GPU configuration which offers just 4 Compute Units or 256 stream processors.

Coming to the advantages of using the smaller Zen 4C cores, the most obvious one is the smaller die size which leads to higher density and increased power efficiency. AMD states that Zen 4C cores offer:

Efficiency:

Scalability For Premium:

Scalability For Entry-Level:

With these smaller cores, AMD is all set to offer increased core counts in future APU variants by mixing Zen-Dense with Zen-Classic cores. There are already rumors which have suggested AMD increasing the core counts of its next-generation Ryzen 8000 "Strix Point" APUs with up to 12 core SKUs in Zen 5 and Zen 5C flavors.

Besides the core count increase, the use of smaller cores also helps AMD scale down to entry-level platforms, offering more options to consumers who are invested in the thin and light segment. On power scaling, the standard Ryzen 7040 and the hybrid designs perform mostly similarly with Zen 4C designs offering slightly better performance at lower TDPs while closing in on the classic design in higher TDP workloads.

According to AMD themselves, the Zen 4 core is better optimized for single-threaded frequency and multi-threading scaling with power above 20W while the Zen 4C cores are optimized for multi-core efficiency and size. AMD seems to have laid the groundwork for its future hybrid chips and it looks like we are going to see more designs in action in the coming Zen 5 generation in 2024 and beyond.