The Snapdragon S4 started shipping in February, and the number that should stop you is not a clock speed. It is the integration. The MSM8960 packs a custom dual-core Krait CPU and a fourth-generation LTE modem onto a single piece of silicon in a 28nm process, and that combination is something no rival can match this year. Everyone else who wants LTE in a phone right now is bolting on a separate modem next to the application processor and paying for it in board space, battery life, and heat. Qualcomm is shipping it as one chip. I have been waiting two years for someone to do this cleanly, and Qualcomm got there first because it is the only company that builds both halves.
Krait is the custom core Qualcomm promised last year, and it has arrived swinging. It is Qualcomm’s own ARMv7 design, in the same conversation as ARM’s Cortex-A15 for raw capability, but drawn from scratch by Qualcomm rather than licensed off-the-shelf. The early benchmarks are not subtle: an MSM8960 turning in an overall system score around 900, where the Cortex-A9 phones of last season sat in the 500s and 600s, and a dual-core Krait edging out a quad-core Tegra 3 in raw processing tests. Read that twice. Two of Qualcomm’s cores beat four of Nvidia’s. That is the payoff of designing your own core and clocking it where you want rather than taking what the reference design gives you.
The 28nm jump is the other half of why this works. Moving down from 45nm buys a real efficiency improvement, and Qualcomm leans on TSMC’s 28nm gate-last HKMG process to get it. It spends that efficiency on a feature it calls asynchronous SMP, where each core sets its own voltage and frequency independently based on what it is actually doing. Most multi-core designs run their cores in lockstep or in coarse clusters. Qualcomm lets every core idle or sprint on its own. On a device where battery is the constraint that actually determines whether a phone is good, that per-core control is worth more than another 200 MHz at the top end.
The lineup is laid out the way Qualcomm always does, from the cut-down S4 Play parts up to the Pro. The one I would point at past the MSM8960 is the APQ8064, the quad-core Krait that landed this summer and brought the new Adreno 320 GPU with it, a genuine step up in graphics for the phones and tablets that want it. The dual-core parts carry the older Adreno 225, which is the Adreno 220 given room to breathe on 28nm and clock higher. Either way, you are getting a chip that does more work per watt than anything Qualcomm shipped before.
The competition is quad-core-happy, and I think it’s slightly missing the point. Nvidia is selling Tegra 3 on the count of cores. Samsung’s Exynos 4 Quad is strong, and Apple’s A5X is a graphics monster in the new iPad. But none of the merchant chips integrate the modem, and TI is visibly losing interest in the merchant apps-processor business altogether, which is its own quiet eulogy I will not write here. Qualcomm, meanwhile, is in something like 40% of smartphones and climbing; it shipped an Android SDK at its Uplinq developer conference to lock developers into its hardware features, and it is working directly with Microsoft to make sure Windows Phone 8 runs best on Snapdragon. The platform play keeps compounding.
You can already see the S4 turning up in the interesting hardware. OPPO’s Finder, the thinnest phone in the world right now, runs an S4-class Snapdragon, which is a useful tell: when a company whose entire pitch is industrial design picks your chip, it is because the chip runs cool and small enough to disappear into a 6.65mm body.
I will say the thing I actually believe: the dual-core Krait with an integrated LTE modem is the most important mobile chip of the year, and the core count on the box is the least interesting thing about it. Qualcomm spent years owning the modem and a year proving it could build a real CPU. The S4 is the first time both facts live on the same die. That is not a spec bump. That is the shape of every phone chip that comes after.