AMD's upcoming "Strix Halo" APU is one of the more exciting chips, with specs that rival consoles and the promise of more efficient and affordable portable gaming. Now new rumors have surfaced of a possible chiplet design featuring the exact same 8-core CPU CCD as AMD's next-generation Zen 5 desktop processor.

This particular information dump comes courtesy of some slides posted on the Chiphell forum. The slides show an AMD Strix Halo APU (also called Sarlak) consisting of a pair of 8-core Zen 5 CCD or Core Chiplet Dies and a monster SoC tile that includes various I/O features, a memory controller, and Strix Halo's signature awesome iGPU also known as Sarlak) is shown.

Getting back to the iGPU, the idea of Strix Halo as a chiplet design is new but makes sense: cram in 16 Zen 5 cores and a big iGPU and you get a huge monolithic chip. Therefore, it makes sense to split everything up, as Intel did with its latest Meteor Lake CPU for notebooks.

The fact that Strix Halo is said to use the same Zen 5 CCD as AMD's next-generation desktop CPUs also means that it will offer the full cache memory allocation of these desktop chips, including L3 cache. AMD's existing laptop APUs may be more affected than others by some applications because of the reduced cache memory.

Unfortunately, gaming is one application that tends to suffer when cache memory is reduced. This is why AMD's desktop APUs have not been great gaming chips, as was the case when we reviewed the Ryzen 7 8700G.

If this is good news, efficiency is a question mark. Chiplet designs tend to be less efficient than monolithic chips; add 16 full-spec desktop cores, a 256-bit bus, and a big iGPU, and it seems unlikely that the battery will last all day. If battery life is not a concern, a full-discrete GPU in a gaming laptop would be a better choice. [Indeed, the appeal of the Strix Halo is the possibility of a simplified, single-chip laptop that is cheaper and more efficient without a dedicated GPU, but still delivers excellent gaming performance.

Of course, the exact source of these slides is not certain; the title of the Chiphell forum post is "Some information and speculation about AMD Strix Halo". While the data presented is plausible, the slides do not immediately appear to be an internal AMD presentation.

Indeed, with items such as "small probability" and "Like Navi31," it seems almost certain that these slides are not from AMD at all, but are based on whatever information the poster has obtained from sources.

Anyway, what about that mega iGPU? In simple architectural terms, it would mean that it has the same number of CUs as the Radeon RX 6700 XT.

However, the Strix Halo has what is called RDNA 3.5-specification GPU technology; what RDNA 3.5 does to the RDNA 3 technology in existing Radeon RX 7000 series GPUs such as the 7800 XT and 7900 XT, for example. exactly what upgrades it will bring is not clear.

However, recent leaked documents regarding the upcoming Sony PS5 Pro may provide a hint. The updated RDNA graphics for the console are said to boost ray tracing performance by 2 to 4 times compared to the RDNA 2 graphics on the standard PS5.

The story got complicated, but the bottom line is that if RDNA 3.5 is associated with the PS5 Pro's new GPU, it could significantly improve ray tracing performance. Anyway, in terms of graphics performance, Strix Halo has another trick up its sleeve. While all existing APUs are hampered by a 128-bit memory bus, Strix Halo offers a full 256-bit bus, which significantly increases memory bandwidth.

According to the slides, the total bandwidth is quite healthy at 500 GB/s, even though it is shared by the iGPU and 16 Zen 5 cores. The slides also show 3DMark benchmark results that position Strix Halo between Nvidia's RTX 4060 and RTX 4070 mobile chips.

Notably, the 3DMark Port Royal test, the primary test for 3DMark ray tracing performance, also maintains this positioning. While many questions remain in terms of battery life and price, all are thoroughly intriguing and promising.

Oh, and availability. We initially expected the Strix Halo to arrive later this year. Its smaller, single-chip sibling is expected in 2024. However, the latest information indicates that the Strix Halo will be a 2025 product.

If this is correct, it will spend most of its operating period competing against Nvidia's next-generation mobile GPUs, probably called RTX 5060 and RTX 5070. And their performance may be different. Watch this space.