Modest Modernization For Low-End Mobiles

Qualcomm announced this morning its next-generation Snapdragon 4-class mobile SoC, the aptly named Snapdragon 4 Gen 2. The company’s new entry-level SoCs for smartphones and other devices include hardware updates that should provide a modest performance boost for most users. Additionally, supporting the more recent 5G standard and manufacturing the chips on a new process node will allow Qualcomm’s overall Snapdragon product stack to be tightly aligned.

First and foremost in terms of performance, Qualcomm claims a 10% increase in CPU performance due to increased CPU core clock speeds. The Snapdragon 4 Gen 2 uses the same 2+6 CPU core configuration as the previous generation Snapdragon 4 Gen 1, combining two Cortex-A78 derived Kryo CPU cores with six Cortex-A55 derived cores. Thanks to the node shrink, Qualcomm boosted the top clock speed of each set of cores by about 10%, with the A78 cores up to 2.2 GHz and the A55 cores up to 2.0 GHz. So a 10% CPU performance improvement should be fairly consistent for both single-threaded and multi-threaded workloads.

Architecturally, there is little left unsaid about these cores. These are decent performance CPU cores, but their age and lack of higher clock speeds means their performance potential is limited. The ultra-budget nature of the Snapdragon 4 series means this will be the last piece in Qualcomm’s stack to move to any kind of Armv9 core. Interestingly, the 4 Gen 2 is slightly better than the 6 Gen 1 when it comes to A55 cores. 6G1’s tiny core only goes up to 1.8 GHz, even though it’s manufactured on the same process node. So this should close the CPU performance gap between those parts a bit (at least until the obligatory his 6 Gen 2 comes along).

Qualcomm, on the other hand, has been quiet about GPU performance. The company stopped giving external part numbers to its GPUs a few years ago and hasn’t even announced performance expectations when it comes to the Snapdragon 4 release. So don’t expect any gains here, especially since the chip is still intended to drive HD/FHD devices.

As mentioned earlier, Qualcomm has moved its entry-level SoC to the Samsung 4nm process (think 4LPP given the timing). That means Samsung’s entire current product stack (Snapdragon 8G2, 7+G2, 6G1, and 4G2) are all made with some flavor of his 4nm node. Samsung’s is the weaker of his two offerings, but it’s almost certainly cheaper. This is a boon for price constrained entry-level parts. Academically, I’m curious how small the Snapdragon 4’s die is based on this process. It should be pretty small, though, so that’s not a detail Qualcomm usually shares.

Otherwise, this latest Snapdragon 4 class SoC is a bit of a give and take release when compared to the 4 Gen 1. On the memory side, the new SoC incorporates Qualcomm’s new controller design, bringing LPDDR5X support to his 4th generation. -Equipped with a chip in its class for the first time. Like other Qualcomm SoCs, this chip can run its memory at speeds up to LPDDR5X-6400. Meanwhile, LPDDR4X will also continue to be supported with his usual LPDDR4X-4266 data rate. The memory bus width is still a total of 32 bits, so LPDDR5X yields a peak memory bandwidth of 25.6 GB/s. That’s a full 50% increase in bandwidth over what 4th Gen 1 can offer.

The storage controller has also been updated to support UFS 3.1, finally bringing Qualcomm’s low-end chips to the relatively newest version of the flash storage standard. Compared to the UFS 2.2 specification supported by previous chips, UFS 3.1 more than doubles the bandwidth per lane. So in a 2-lane configuration, 4G2 can theoretically transfer as much as 2.9 GB/s of data, but Qualcomm makes no claims about performance. Notably, support for eMMC storage isn’t listed in his Qualcomm specs, signaling that support for the now-obsolete interface standard is finally heading into the sunset.

When it comes to Qualcomm’s imaging ISP and related hardware, the 4th Gen 2 will take a step back with the removal of the third camera pipeline. As a result, the 4 Gen 2 only supports up to 2 cameras. The Spectra ISP itself is seemingly unchanged, with Qualcomm still using a 12-bit design. This camera shift slightly changed the overall imaging capabilities of the SoC, even in a two-camera configuration. Balanced supported resolutions in dual camera zero shutter lag mode. The SoC runs at (up to) 16+16M pixels instead of 25+13M pixels.

Qualcomm is touting better camera performance, although it supports fewer camera modules. Qualcomm, in particular, says that his new SoC will offer faster autofocus support than the 4th Gen 1, as well as the latest electronic image stabilization. The 4th Gen 2 also includes an “AI-enhanced” low-light feature, with Multi-Camera Temporal Filtering (MCTF) support built into the SoC for noise reduction.

Another major hardware improvement for the SoC is an upgrade to the Snapdragon X60 series class modems. New to Qualcomm’s lineup is the Snapdragon X61 modem, a scaled down version of his X62/X65 modems found on other chips. Compared to the future 4 Gen 1 SoC and its X51 modem, X61 will support the new Release 16 version (aka). 5G Phase 2) of the 3GPP family of standards.

Release 16 is currently scheduled to be released three years ago, so this is a necessary update to keep up with the development of 5G networks. However, since the primary benefit of Release 16 is on the network operations side rather than the consumer side, mobile phone buyers will see little benefit other than some improvement in coverage. For 4th Gen 2, the actual bandwidth numbers are unchanged from 4th Gen 1. That means downloads and uploads top out at 2.5 Gbps and 900 Mbps respectively.

Once again, millimeter wave support remains left out of Qualcomm’s spec sheet. With the 4th Gen 1, it became a hidden feature of sorts – the hardware was there in case handset vendors wanted to use it, but Qualcomm didn’t advertise it – and It’s unclear if Qualcomm even cared about the hardware for this new feature Silicon.

Also of note: Bluetooth 5.2 support has disappeared from Qualcomm’s specs. The 4 Gen 1 supported BT 5.2, but Qualcomm’s entire documentation states that the 4 Gen 2 only supports BT 5.1. This is notable not only because it’s a regression, but because Bluetooth Low Energy audio is a feature of 5.2. of 5.2 Features. At the moment, it’s unclear why Qualcomm would want to remove this feature from its low-end SoCs (although there were suspected royalties, LE Audio’s LC3 codec is part of his BT license). Otherwise, his Wi-Fi half of Qualcomm’s wireless system will remain unchanged and support Wi-Fi 5.

To wrap things up, Qualcomm says that some of the usual suspects, including Redmi and vivo, are set to adopt the Snapdragon 4 Gen 2. Devices equipped with this SoC will be announced in the second half of this year.