Samsung Galaxy S 4’s Quad-Core/Octa-Core Chipsets Are Focused On Efficiency And LTE

Much about the Galaxy S 4, Samsung’s new flagship smartphone, is the company remixing its Galaxy S III formula — with no big changes to the design or UI look and feel, and new software features such as face tracking additions like Smart Scroll and Smart Pause that add to and build on what came before. On the hardware side Samsung is also following its prior pattern, putting different chipsets in the U.S. and international versions of the phone as it did with the S III. So while the U.S. S 4 has a 1.9GHz quad-core chip, the international version gets a 1.6GHz octa-core chip.

Samsung did not confirm exactly what the U.S. chipset is at yesterday’s launch, but the word on the street is it’s Qualcomm’s Snapdragon 600. The international S 4 chipset, however, is apparently Samsung’s own Exynos 5 chip, which is built on ARM’s big.LITTLE architecture — so what you’re really getting is a quad-core phone with two clusters of four chips that it switches between, depending on how taxing whatever you’re asking it to do is.

Octa-Cores vs Eight Cores

“It isn’t an eight-core chip in the traditional sense of eight cores — it’s not like the same jump from dual-core to quad-core,” says Nick Dillon, analyst at Ovum. “The lower powered cores run when it’s just idling in the background and then when you need the full power it kind of clicks over to the other one.”

So this is not a case of the U.S. getting shortchanged on S 4 cores, rather it’s just two different approaches to achieving similar power-plus-efficiency ends — all the more important for a phone with such a big screen (pushed up to a full ‘phablet’ 5 inches from the S III’s slightly more modest 4.8-inch pane).

“I guess somebody like Qualcomm would probably argue they don’t need to have that complexity [of octa-cores] because what they’re able to is dial down the power of their main chip to a lower power when it just needs to idle,” Dillon adds. “They can adjust the clockspeed and the power that goes into them on the fly so they really don’t need this compromise of having four extra chips.”

Speaking to TechCrunch at the Mobile World Congress tradeshow in Barcelona last month, Qualcomm’s Raj Talluri, SVP of product management, did argue just that — saying the chipmaker is focused on “heterogeneous compute” for the next generation of chipset innovation, or getting the various components to work together better, rather than just sticking in more cores.

“Clearly we will do the right number of cores to get the right performance but that’s not all we focus on,” Talluri told TechCrunch, pointing to video, audio, camera, LTE, touch input, gestures, different forms of user interface, noise cancelling tech, gaming and more as all areas the chipmaker now has to consider. “If all we had to do was multicore my job would be very easy.”

So which approach is best? Four big cores that can act like they’re little or a pair of big and small quad-cores? At this early point it’s hard to say, until the comprehensive benchmarks and real-world tests start rolling in.

“Whether [Samsung’s octa-core chip is] actually going to bring any real world benefit in terms of top end speed or in fact battery life… we’ll have to see,” says Dillon, adding: “This is the  first device with the chip in it — the first phone at least.”

Of course, from a spec sheet point of view, Samsung’s octa-core boast might garner a little more attention than the quad-core label. “From a marketing point of view, it obviously sounds impressive,” adds Dillon. “It’s still a specs race at the top end. You’ve got to have the fastest process so if you’re able, through your own technology, to include what looks like an even better processor — on paper at least — then you’ve got to.”

But marketing vanity metrics won’t win you long term customer loyalty if the overall experience is poor. And while mobile apps that truly tax multicore chips remain thin on the ground, every mobile user knows what it’s like to run out of juice — hence both Samsung and Qualcomm are focusing on making less wasteful use of all that power sitting in our pockets.

LTE

Why can’t Samsung just stick its own Exynos chip across the board in the S 4? The answer is likely to be LTE/4G — underlining once again how Qualcomm’s decision to wrong-foot the competition by moving quickly on LTE continues to pay off for mobile’s No. 1 chipset maker.

“Samsung is not as advanced in terms of their LTE modem development as Qualcomm are, who are by far the leaders in that space,” notes Dillon.

IHS Screen Digest analyst Ian Fogg also explains the chip variation between geographies as “almost certainly” down to “LTE maturity in terms of bands available” — since the processor is integrated with the LTE hardware (and different LTE bands are in use in different parts of the world).

While Samsung has now got LTE connectivity in its own modem, it’s likely they don’t have support for commonly used bands in the U.S. such as 700Mhz, says Dillon.

“Maybe they’ve had to fall back on Qualcomm to provide that variant, that connectivity in that market,” he adds. “You can imagine that if that capability was there they’d stick their chip in everything.”

Quad-Core Apps

What about apps? Is there much making use of quad-cores at this point? “It’s hard to tell whether Samsung are making the most of all this extra power,” concedes Dillon. Many of the Samsung software additions to the S 4 are focused on the camera, with apps like dual record and dual shoot, but such apps are likely to be able to lean on dedicated image processing hardware to do the grunt work, rather than requiring massively multicore processors.

“We’ve kind of got to the point where most dual-core chips and definitely quad-cores, there’s nothing really that pushes the limits of them,” adds Dillon. “There are a few very specific applications — some augmented reality stuff for example is pushing the boundary but the majority of what you’re doing on most phones, switching between apps, general usage, you’re not going to see any difference.

“So I think the focus has shifted somewhat to power efficiency and battery life — which is where the whole big.LITTLE thing comes in. Having the high power but also using less power meaning you can actually make it through the day on a charge — which is a real issue.”

The multicore race for mobiles may not quite be over — at least not on the marketing front — but it looks like a war of diminishing returns at this point. “I think it will be of reducing interest for consumers,” concludes Dillon. “I don’t think consumers will see a direct benefit from it. Never mind looking on paper but in terms of reality — having a quad-core over an eight core, whether you’ll actually see any difference between those is debatable.”

It’s pretty much the same point Qualcomm’s Talluri made last month, when asked whether phones actually need eight cores: “We definitely haven’t said eight cores, we said we have four good ones,” he told TechCrunch.

But Talluri did point to some apps — such as video games and a video editing application Qualcomm was demoing at MWC — as examples of software that is beginning to tax quad-core hardware.

He also suggested video is are an area where quad-core chips have the potential to support new types of (disruptive) experiences and applications. “Slowly applications are catching up to using multicore,” he said. “We have very nice video editor application – the first real quad core application I think that’s not a gaming or a browser. And you can see as you plug in more cores the performance is better.”