Mar 23 AT 12:06 PM Taylor Wimberly 64 Comments

A closer look at Samsung’s killer 2 GHz Exynos 5250


Two years ago ARM Holdings announced their new architecture that would replace the Cortex-A9 CPU core found in most of today’s Android phones and tablets. Codenamed Project Eagle, the new Cortex-A15 CPU was dubbed an “Intel killer” since it was designed for a wide range of devices, including low-power servers, and boasted speeds up to 2.5 GHz.

Eric Schorn, VP of Processor Marketing ARM, said that A15 is “The biggest thing ARM has ever done, the degree of commitment is truly phenomenal. It’s like taking a desktop and putting it in your pocket.”

As most Android fans know, new phones come out every other week and it’s a difficult choice knowing when to upgrade your device. However, we only see a new CPU architecture released every 2-3 years. For this very reason, many of us have been waiting to see who releases the first chip with an ARM Cortex-A15 CPU core.

NVIDIA, Samsung, ST Ericsson, Texas Instruments and a few smaller players have all confirmed or hinted at new parts based on Cortex-A15, so it’s been exciting to watch them compete and see who can come to market first.

Based on all the information we gathered at CES and Mobile World Congress earlier this year, it has become clear that Samsung will be the first company with a chip that includes Cortex-A15. The average consumer doesn’t care what processor is inside their phone, but if you do then read on to brush up on the latest details.

Enter the Exynos 5250

Regular readers of the site are probably familiar with Samsung’s Exynos 5250. It was first announced last year and processor nerds like me have been obsessed with it ever since.

Back in January we were the first to reveal some of the details about the Exynos 5250 when we interviewed an executive from Samsung LSI at CES. They told us that Exynos 5250 would feature dual-core 2 GHz Cortex-A15 CPUs (that we already knew), but they surprised us with the news that it would feature an ARM Mali-T604 GPU.

Some people doubted our info about the Mali-T604 GPU, but this week Charlie Demerjian of SemiAccurate confirmed the details with a leaked slide from the Common Platform technology forum. There wasn’t anything we didn’t already know in the slide, but we felt it was a good chance to take a closer look at the Exynos 5250.

Samsung’s 32nm HKMG process technology

The move from 45nm to 32nm reduces power consumption.

Samsung’s main advantage over the competition is that they own their own fabs where these processors are produced. Other companies like NVIDIA or Qualcomm are fabless and outsource their production to companies like TSMC or Global Foundries.

Most of Samsung’s mobile application processors are produced in Korea, but they just spent $3.6 billion to upgrade their fab in Austin, TX to boost capacity. Recent rumors suggest that the Austin fab is currently producing Apple’s A5 chip for the iPhone, but we believe they are also producing the Exynos 5250.

Since Samsung has their own fabs, they use a different process technology to produce their chips. Their latest process node is 32nm High-k Metal Gate (HKMG), which reduces power consumption. This is the industry’s first HKMG process.

I won’t pretend to know what all of this means, but the benefits of 32nm HKMG include:

  • 2x gate density increase (Superior area scaling with Gate-First HKMG)
  • >100x lower gate leakage
  • >40% delay improvement at fixed leakage
  • ~10x leakage reduction at fixed speed
The main takeaways here are that Samsung’s 32nm HKMG process allowed them to be first with Cortex-A15 and it reduces CPU/GPU power consumption by around 40-50% compared to their 45nm process technology.

ARM Cortex-A15 CPU core

“The ARM Cortex-A15 brings unparalleled performance to our Exynos processor family and the exploding mobile marketplace,” said Dojun Rhee, vice president of System LSI marketing, Device Solutions, Samsung Electronics. “Designers need an application processor platform that delivers full high definition multimedia capabilities, fast processing speed and high performance graphics to meet end users expectation for a connected life on the go. The advanced low-power, high-performance processor technology of the new Exynos 5250 continues to deliver an unprecedented level of performance for users to enjoy a completely new mobile experience.”

So how fast exactly is Cortex-A15? It is capable of processing 14 billion instructions per second (DMIPS, Dhrystone million instructions per second) at 2.0 GHz. That’s almost double the performance over a current Cortex-A9-based dual core processor running at 1.5 GHz, capable of 7,500 DMIPS. It also means it should be faster than Qualcomm’s new Snapdragon S4 and NVIDIA’s Tegra 3.

Memory bandwidth has been increased to a staggering 12.8 Gigabytes per second (GB/s). Once again, that is double the 6.4 GB/s maximum found in current dual-core Cortex-A9 processors.

For even more nerdy details, head over to ARM’s official documentation on Cortex-A15.

ARM Mali-T604 GPU core

No consumer devices have used the ARM Mali-T604 GPU, so we don’t have a lot to compare it with. However, Samsung says it will offer about a 400% improvement over the current Mali-400 GPU found in the current Galaxy S II models.

Massimiliano Villani, Senior Manager Mobile Marketing for Samsung, said “We benchmarked several GPUs and we found that the overall architecture of the Mali family provided by ARM is nowadays the best in class for GPU performance.”

One of the main benefits of the faster GPU is the ability to drive super high resolution displays. Exynos 5250 supports resolutions up to WQXGA (2560×1600), which is similar territory to the new iPad retina displays (produced by Samsung).

Exynos 5250 is also equipped with embedded Display Port (eDP) interface, compliant with panel self refresh (PSR) technology. This technology instructs the application processor not to send image data to the LCD panel when the set is displaying still image, reducing power consumption.

If you are a graphics freak, check out ARM’s official documentation on Mali-T604.

Coming to a tablet or smartphone near you?

Some may remember that I wrote Samsung would unveil the rumored Galaxy Tab 11.6 at Mobile World Congress, which didn’t happen. That prediction came from a prototype device I saw at CES, but the rumor actually goes back to last year. We don’t know exactly when it will happen, but we still believe Samsung will introduce a next-gen Galaxy Tab with a dual-core 2 GHz Exynos 5250 sometime this year.

I think the more interesting story is what happens with the Galaxy S III. This flagship device has long been rumored to use Samsung’s quad-core Exynos 4412, but I’m not so sure if that will happen. It doesn’t make much sense to me to use a chip that features the older Cortex-A9 CPU and Mali-400 GPU when Samsung is on the verge of releasing their first Cortex-A15 part.

In our recent Android Rumors Report, I said there was about a 50% chance the Galaxy S III would use Exynos 4412 and a 50% chance it would use Exynos 5250. Having thought about it some more, I’d say the odds are actually much greater that the Galaxy S III will feature Exynos 5250.

Samsung’s official Exynos 5250 documentation reveals that the part will initially come in two versions. One is clocked at 2 GHz (for tablets), and the other is clocked at 1.7 GHz (for smartphones).

In the Cortex-A15 video above, Yiwan Wong, VP SoC Marketing Group, Samsung Electronics, said “We believe this new core will be the enabler for many exciting next-generation mobile products, such as smartphones and mobile computing devices.”

Earlier this year I wrote, “One not so far off possibility for the Galaxy S III could be the Exynos 5250. This part is slated for the second-half of 2012, but Samsung could leap-frog the competition with the first mobile device to feature the next-generation ARM Cortex-A15 CPU and ARM Mali-T604 GPU. This would require a delay of the Galaxy S III from its normal summer release schedule, but it’s the choice I’d make if I was in charge.”

We now know from a recent earnings call that Samsung’s Exynos 5250 will enter mass production in Q2, so I’m not really sure they would need to delay the Galaxy S III that much. This is the same company that re-engineered the original Galaxy Tab 10.1 in one month, to make it thinner than the iPad 2.

Seeing that Apple went with their A5X chip (dual-core A9) in their new iPad, it makes even more sense that Samsung would make an effort to one up their rival. Now every time a month passes and we hear nothing official about the Galaxy S III, it increases the chances they are going with Exynos 5250.

If that turns out to be true, then I wouldn’t want to purchase a smartphone right now that could be virtually obsolete within a couple months.

Taylor is the founder of Android and Me. He resides in Dallas and carries the Samsung Galaxy S 4 and HTC One as his daily devices. Ask him a question on Twitter or Google+ and he is likely to respond. | Ethics statement

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