MediaTek enters the 4th Dimensity with 3nm octa-core 9400 smartphone brains

Still sticking with Arm and not taking RISC-Vs

by · The Register

Fabless Taiwanese chip biz MediaTek has unveiled the fourth flagship entry in its Dimensity family of system-on-chips for smartphones and other mobile devices. It's sticking with close companion Arm rather than jumping ship to RISC-V for the CPU cores, for those wondering.

The Dimensity 9400 processor – a rival to Qualcomm's Snapdragon series and Apple's own silicon – is continuing from the previous generation with an eight-core approach, with one Arm Cortex-X925 CPU core topping out at just over 3.6GHz, three Cortex-X4s rated up to 3.6GHz, and four Cortex-A720 cores running up to 3.3GHz. MediaTek dubbed this an "all big core" arrangement as opposed to the big-little core configuration seen in the Arm world.

This is all fabbed on TSMC's 3nm process node, and sports 29.1 billion transistors, according to the designers. This node helps make the chip up to 40 percent more power efficient than the TSMC 4nm previous generation, the 9300, it's claimed.

MediaTek's top-level summary of its latest flagship Dimensity mobile chip, the 9400, from a media briefing – Click to enlarge

We're told the 9400 has double the L2 cache of the previous gen, and 50 percent more L3. Single-threaded performance has apparently been boosted by up to 35 percent in GeekBench 6.2 tests, and multicore by up to 28 percent. The 9400 is aimed at higher-end devices, and is hoped to follow in the footsteps of the 9300 and help grow MediaTek's sales.

"From a business perspective, last year, 2023, we did over a billion dollars of revenue in just the flagship segment," a MediaTek spokesperson told The Register. "Our CEO and CFO have already said that we'll see over 50 percent growth year on year and are on track to take over $1.5 billion this year."

It's not a product launch these days without AI being mentioned, and the 9400 is said to pack an eighth-generation machine-learning-accelerating neural processing unit (NPU), which MediaTek claims is as much as 80 percent faster at performing LLM prompt inference over the previous NPU, and is also as much as 35 percent more power efficient.

Presumably that'll need software optimized for or targeting that hardware. Speaking of which, the latest SoC includes what's called a Dimensity Agentic AI Engine that, among other things, is supposed to provide a unified way of connecting applications to various models, neural network hardware acceleration, and generative services – whether that's all or partly local on the device or remote in the cloud. That may be useful for developers.

On the graphics side, the 9400 carries a 12-core Arm Immortalis G925 GPU, with a claimed 41 percent boost in performance and 44 percent power savings potentially. Also on the power savings front, Mediatek has a 4nm Wi-Fi/Bluetooth combo chip that uses up to half the power of the previous generation to beam wireless data at up to 7.3Gbit/sec with an extra 30 meters (98 feet) of coverage – and the Bluetooth has a claimed range of 1.5 kilometers (almost a mile).

Being a top-end design for MediaTek, the 9400 supports triple-screen devices like the one released earlier this year by Huawei. That Mate XT uses its own hardware rather than MediaTek's – if any other manufacturer wants to build the same, the 9400 SoC is an option.

"The MediaTek Dimensity 9400 will continue furthering our mission to be the enablers of AI, supporting powerful applications that anticipate users' needs and adapt to their preferences, while also fueling generative AI technology with on-device LoRA training and video generation," gushed MediaTek president Joe Chen in a canned statement.

"As the fourth-generation flagship chipset, the Dimensity 9400 continues to build on our momentum of steady growth in market share, and MediaTek's legacy of delivering flagship performance in the most efficient design for the best user experiences."

MediaTek launched its silicon just ahead of Qualcomm, which is expected to announce the Snapdragon 8 Gen 4 SoC in the next few weeks. MediaTek reckons its 9400 will appear in phones shipping from the fourth quarter of 2024. ®