New ARM Cortex-A72 nearly twice as fast as -A57
Feb 5, 2015 — by Eric Brown 7,538 viewsARM unveiled an ARMv8 Cortex-A72 CPU for mobile said to be twice as fast as the -A57, plus a faster new Mali-T880 GPU and CoreLink CCI-500 interconnect.
We’ve only recently seen the 64-bit, ARMv8 Cortex-A57 design arrive in mobile system-on-chips, such as Qualcomm’s octa-core Snapdragon 810 and hexa-core Snapdragon 808, both of which mate the -A57 with Cortex-A53 cores Big.Little style. By 2016 we’ll see the newly announced Cortex-A72 replace the -A57, says ARM. While the Cortex-A57 was primarily aimed at servers, the -A72 squarely targets mobile, and will often be seen mated with the -A53 in Big.Little configurations.


Cortex-A72 block diagram (left) and in a typical Big.Little SoC configuration
(click images to enlarge)
Using TSMC’s new 16nm FinFET+ node fabrication rather than the 20nm process used by the Snapdragon 810 and 808, the Cortex-A72 will be about twice (1.9x) as fast as the -A57 and 3.5 times as fast as the Cortex-A15, claims ARM. The Cortex-A57 can be clocked at up to 2.5GHz in a 16nm FinFET process, and uses 75 percent less energy than the -A15, claims ARM. It supports one to four SMPs within a single processor cluster, and multiple coherent SMP processor clusters through AMBA 5 CHI or AMBA 4 ACE technology.
The Cortex-A72 was announced along with a new POP IP for TSMC’s 16nm FinFET, a Mali-T880 GPU, and CoreLink CCI-500, the first new ARM interconnect since the CCI-400 was announced three years ago. These components, along with new Mali-V550 video and Mali-DP550 display accelerators, are all being marketed as part of a 2016 Premium Mobile Experience framework.
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HiSilicon, MediaTek, and Rockchip have already promised Cortex-A72 SoCs for delivery in mobile products in 2016. Meanwhile, GizmoChina published what it claims are leaked specs of new Qualcomm Snapdragon 620 and 618 SoCs that incorporate the -A72 in octa- and hexa-core designs, respectively. Both mate the -A72 with -A53 cores. (GSMarena first picked up on the GizmoChina post.)
While primarily focused on smartphones, phablets, tablets, and convertibles, the Cortex-A72 can also be applied to digital TV device, automotive computers, servers, and wireless and networking infrastructure, says ARM. Together with the new 850MHz Mali-T880 GPU and the new video co-processors, the Cortex-A72 is said to deliver video at up to [email protected] resolution.
Mali-T880 GPU
The Mali-T880 GPU is scalable from one to 16 cores and delivers 1.8 times more performance and 40 percent more energy efficiency than the Mali-T760 GPU, claims ARM. Native support for 10-bit YUV provides “stunning fidelity for premium 4K content,” says the U.K.-based chip IP designer.

Mali-T880 block diagram
(click image to enlarge)
Other key new Mali-T880 features include quad prioritization for better UI and “casual content” performance, as well as enhanced “Forward Pixel Kill,” which improves performance in advanced use cases by eliminating redundant work early in the pipeline, says ARM. The new POP IP can also apply TSMC’s 16nm FinFET+ process to the Mali-T880.
The new CoreLink CCI-500 Cache Coherent Interconnect, which enables the Big.Little communication between the -A72 and -A53 cores, delivers double the peak memory system bandwidth (34GB/s) and offers a 30 percent increase in processor memory performance compared to the CoreLink CCI-400, claims ARM. CoreLink CCI-500 supports ARM TrustZone security, and “delivers system power savings thanks to an integrated snoop filter,” says ARM. The snoop filter is said to maintain a directory of cache contents that frees up bandwidth and lets the CPU either save power or redirect resources.

CoreLink CCI-500 Cache Coherent Interconnect block diagram
(click image to enlarge)
The new Mali-V550 video co-processor supports HEVC decode and encode on a single core, and can scale up to 4K120fps with eight cores. The Mali-DP550 display co-processor, meanwhile, can offload tasks such as composition, scaling, rotation, and image post-processing from the GPU to maximize battery life, says ARM.
Testimonials include supporting quotes from HiSilicon, MediaTek, and Rockchip, as well as promises of tools support from Cadence and Synopsis. Meanwhile, Suk Lee, TSMC Senior Director, Design Infrastructure Marketing Division had this to say: “The combination of TSMC 16FF+ process technology and the implementation advantages of ARM POP IP gives our customers the opportunity to rapidly bring highly optimized mobile SoCs based on Cortex-A72 to market in early 2016.”
Further information
The Cortex-72 and entire suite of 2016 Premium Mobile Experience products will appear in mobile devices starting in 2016, says ARM. More information may be found in ARM’s Cortex-A72 and Premium Mobile Experience announcement, as well as ARM’s product pages for the Cortex-A72, the Mali-T880, and the CoreLink CCI-500.
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