Back at the beginning of the year, Samsung announced with much fanfare the Exynos 5410, a.k.a. Exynos 5 Octa, a big.LITTLE processor featuring a cluster of four ARM Cortex A7 cores clocked at 1.2GHz and four ARM Cortex A15 cores clocked at 1.7GHz.
The idea of this setup was to provide the best of two worlds, by intelligently switching between the A7 cores, useful when low power consumption is desirable, and the A15 cores, which could provide the oomph needed for processor intensive operations.
The Octa is limited to cluster-migration because of a hardware deficiency.
However, as it turned out, there’s a problem that prevents the chip from working as ARM, the mastermind behind the big.LITTLE architecture, intended. Put simply, the cache system that should allow the two types of cores to come online as needed to maximize efficiency isn’t working properly on the Exynos 5410. For that reason, only one core cluster can be active at a time (cluster migration), so you can’t have all eight cores running at the same time (which is why some called the Octa name deceptive) and you can’t have, say, two Cortex A15 cores and two Cortex A7 cores running in tandem.
This hardware deficiency, which Samsung doesn’t publicly acknowledge, is said to be one of the reasons why so few units of the Galaxy S4 are equipped with an Exynos 5 Octa processor, and why the Note 3 will reportedly also be powered by a Snapdragon 800 chip.
For an in-depth explanation of the Exynos 5 Octa cache issue, check out this piece from my colleague Daniel Charlton.
Enter the Exynos 5420
The Exynos 5420 is a refreshed version of the Exynos 5 Octa that brings higher clock speeds, a new GPU, and, hopefully, a functional cache system that would allow the chip to truly make use of the big.LITTLE design.
Announced today, Exynos 5420 features the same four core clusters, with A7 cores running at up to 1.3GHz and A15 cores running at up to 1.8GHz. That’s, in both cases, 100MHz more than the previous generation. According to Samsung, the new CPU offers 20 percent “better performance over the predecessor by optimizing the power-saving design”
Another big change is the replacement of the Imagination PowerVR SGX544MP3 GPU found on the Exynos 5410 with an ARM Mali-T628 MP6 GPU. The new six-core processor is capable of General-Purpose computing on Graphics Processing Units (GPGPU), which is a technology that enables the GPU to take over some complex computing tasks from the CPU, OpenGL ES 3.0, and Full Profile Open CL 1.1.
The new GPU should bring a marked improvement in graphics performance compared to the rather old PowerVR GPU on the earlier generation. Samsung claims that the graphic performance capabilities of the new SoC are “two times greater” than the old one, which is a bit vague, but not unreasonable to believe.
Now for the big question – has Samsung fixed the cache problem that hamstrung the Exynos 5410? We don’t know for now, but expert Anand Lal Shimpi of AnandTech, thinks that the update would be “senseless” without the fix.
The release of the new Exynos 5 Octa would be senseless without the fix.
Samsung says in the press release that the Exynos 5420 is now being sampled and that mass production is scheduled to commence in August. That means it’s theoretically possible to see at least some versions of the Galaxy Note 3 running on this new Exynos 5 Octa SoC, though Snapdragon 800 would probably still get the lion’s share.
However, Anand notes that, without a properly functioning cache system, the high power consumption levels of Samsung’s design make the new Exynos 5 Octa more suitable for a high-end tablet rather than a smartphone or small tablet.
Bottom line, the eventual success of Exynos 5420 largely depends on whether Samsung managed or not to make the CPU smarter, and not only faster.
Samsung Brings Enhanced Mobile Graphics Performance Capabilities to New Exynos 5 Octa Processor
SEOUL, Korea, July 23, 2013 – Samsung Electronics Co., Ltd., a world leader in advanced semiconductor solutions, today introduced the latest addition to the Exynos product family with top level of graphic performance driven by a six-core ARM® Mali™-T628 GPU processor for the first time in the industry. With mobile use case scenarios becoming increasingly complex, Samsung’s newest eight-core application processor gives designers a powerful, energy efficient tool to build multifaceted user interface capabilities directly into the system architecture. Samsung will demonstrate the new Exynos 5 family at SIGGRAPH 2013 in the ARM booth, #357; Exhibit Hall C at the Anaheim Convention Center.
Samsung’s new Exynos 5 Octa (product code : Exynos 5420), based on ARM Mali™-T628 MP6 cores, boosts 3D graphic processing capabilities that are over two times greater than the Exynos 5 Octa predecessor. The newest member of the Exynos family is able to perform General-Purpose computing on Graphics Processing Units (GPGPU) accelerating complex and computationally intensive algorithms or operations, traditionally processed by the CPU. This product also supports OpenGL® ES 3.0 and Full Profile Open CL 1.1, which enables the horsepower needed in multi-layer rendering of high-end, complex gaming scenarios, post-processing and sharing of photos and video, as well as general high-function multi-tasking operations.
“ARM welcomes the latest addition to the successful Exynos Octa 5 series, which uses ARM’s Mali GPU solution to dramatically improve graphics performance,” said Pete Hutton, executive vice president & general manager, Media Processing Division, ARM. “ARM big.LITTLE™ and ARM Artisan® Physical IP technologies continue to be at the heart of the Octa series and now complement the new functionality brought by ARM GPU Compute. This combination enables unprecedented capabilities in areas such as facial detection and gesture control, and brings desktop-quality editing of images and video to mobile devices.”
“Demand for richer graphic experiences is growing rapidly nowadays,” said Taehoon Kim, vice president of System LSI marketing, Samsung Electronics. “In order to meet that demand from both OEMs and end users, we developed this processor which enables superb graphical performance without compromising power consumption.”
The newest Exynos processor is powered by four ARM Cortex®-A15™ processors at 1.8GHz with four additional Cortex-A7™ cores at 1.3 GHz in a big.LITTLE processing implementation. This improves the CPU processing capability by 20 percent over the predecessor by optimizing the power-saving design.
In addition, the multiple image compression (MIC) IP block inside this System-on-Chip successfully lowers the total system power when bringing pictures or multimedia from memory to display panel. This feature results in maximizing the usage hours of mobile devices with a high-resolution display such as WQXGA (2500×1600), in particular when browsing the web or doing multimedia application requiring the frequent screen refresh.
The new Exynos 5 Octa processor also features a memory bandwidth of 14.9 gigabytes per second paired with a dual-channel LPDDR3 at 933MHz, enabling an industry-leading fast data processing and support for full HD Wifi display. This new processor also incorporates a variety of full HD 60 frames per second video hardware codec engines for 1080p video recording and playback.
The new family of Exynos 5 Octa is currently sampling to customers and is scheduled for mass-production in August.