Snapdragon 8cx Gen 4 specs surface, promise powerful CPU, support for external GPU
At the end of 2021 Qualcomm unveiled the Snapdragon 8cx Gen 3, the first 5nm chipset for Windows on ARM devices. It used ARM-designed cores, so its performance is not too different from its siblings that are used for Android. But soon Qualcomm’s acquisition of Nuvia will pay off with the 8cx Gen 4.
As previous rumors reported, the company is working on a 12 core chip. According to Kuba Wojciechowski, these will be divided into 8 performance (~3.4GHz) and 4 efficiency (~2.5GHz) cores. They are based on Nuvia’s Phoenix design and will use the “Oryon” marketing name (rather than “Kryo” like the current Android chips).
The Snapdragon 8cx Gen 4 will be quite a beast. Wojciechowski reports that there will be 12MB of shared L2 cache for each block of 4 cores, plus 8MB of L3 cache, 12MB of system-level cache and an extra 4MB for graphics.
Up to 64GB of LPDDR5X RAM will be supported in an 8-channel configuration running at 4.2GHz. Nuvia was originally designing chips for servers (it still is) and those typically have plenty of RAM.
The chipset will have the Adreno 740 built in, the same GPU as the 8 Gen 2. However, an external GPU will be supported with 8 lanes of PCIe 4.0 (as a reminder, v4.0 is twice as fast as PCIe 3.0).
There will be an extra 4 PCIe 4.0 lanes (that can also be configured as two 2x channels) for NVMe drives, though 2 lane UFS 4.0 storage (up to 1TB) is supported too as a cheaper option. The chip will also have additional PCIe 3.0 lanes for peripherals like a Wi-Fi card or a modem. The 8cx Gen 4 will not have a 5G built in (unlike its Android counterpart).
Wired connectivity options seem outstanding. The chip supports two USB 3 10Gbps ports, plus three USB 4 (Thunderbolt 4) ports with DisplayPort 1.4a. The latter will enable it to drive a triple monitor setup, 5K+4K+4K.
A few more tidbits. The Adreno 740 will be usable for machine learning tasks as will the upgraded Hexagon Tensor Processor, which can deliver up to 45 TOPS in INT8. The tricky part will be getting support for it on Windows, but Qualcomm is working with Microsoft and Adobe to figure it out.
The chipset will apparently support video decoding up to 4K/120fps and encoding up to 4K/60fps in various codecs, including AV1 (which Apple’s M2 chips lack).
The Snapdragon 8cx Gen 4 is expected in 2024 and should power Windows laptops and tablets (and possibly mini PCs). Qualcomm has promised to unveil more official details for the new chip later this year.
