It's all in the RISC: Arm legs it to Computex with a head full of Cortex-A77 CPU, Mali-G77 GPUs

That's enough body language puns


Chip design factory Arm is rolling another CPU core off the assembly language line: the Cortex-A77. It'll probably be the brains of high-end smartphones, modest slab-tops, and other devices shipping early next year.

In time for the Computex 2019 industry jamboree in Taiwan this coming week, Arm on Sunday spoke publicly about the A77, a follow-on from last year's Cortex-A76. As such, a single-core A77 is estimated by Arm to have up to 20 per cent higher IPC (instructions per cycle) performance over an A76, when running both at 3GHz on 7nm.

The A77 has, as far as we can tell, no scary surprises. It is an Armv8.2-compatible CPU core capable of running 32-bit and 64-bit application code, with 64KB L1 instruction and data caches, 256 or 512KB L2 caches, and up to 4MB of L3 cache. You can combine up to four of them with four smaller cores, such as the Cortex-A55, into a big.LITTLE arrangement: the A55s doing light tasks until the A77s spin up to run heavier code.

According to Arm's technical docs seen by The Register ahead of today's launch, the A77 has double the A76's memory bandwidth to its branch predictor (64 bytes per cycle), sports improvements to its branch predictor's accuracy, has a 33 per cent larger main branch target buffer (8K entries), and has a four-times larger L1-BTB (64 entries, one-cycle latency).

The front end also features a 1,500-entry macro-operation cache, which can be considered an L0 decoded instruction cache, again increasing performance. The dispatch bandwidth is increased 50 per cent to six instructions per cycle, with a 160-entry out-of-order execution window, up 25 per cent on the previous generation. Integer execution bandwidth is increased 50 per cent, and there's now a second lane for performing AES cryptography.

On the subject of the macro-op cache, it's useful for speeding up instructions that can be decoded and broken into separate operations that are subsequently cached. "A common example is load instructions with an immediate pre-/post-index, where the base address register is also updated," a spokesperson for Arm's engineering team told us. "This instruction is cracked into a load and an 'update' macro-op."

Here's a diagram summarizing the A77:

Arm's overview of the Cortex-A77

Click to enlarge ... Source: Arm

Arm also tore the wraps off its super-scalar Mali-G77 graphics processor design, which features its new Valhall architecture, and its accompanying Mali-D77 display processor and improved neural-network processor unit, all of which, like the A77, are available to license and use in forthcoming system-on-chips. ®

Speaking of licensed designs... PowerVR GPU and neural network accelerator cores are now available to license via SiFive's DesignShare platform, allowing folks creating their own RISC-V system-on-chips to include Imagination's accelerators. SiFive is a developer of customizable RISC-V SoCs and processor blueprints, and also just acquired USB 2 and 3 designs from Innovative Logic as well as most of its team in India.

RISC-V is an open-source instruction set specification backed by Western Digital, Nvidia, Qualcomm, Google, and others – and is keeping Arm on its toes, to quote Arm CEO Simon Segars.

Similar topics


Other stories you might like

  • Drone ship carrying yet more drones launches in China
    Zhuhai Cloud will carry 50 flying and diving machines it can control with minimal human assistance

    Chinese academics have christened an ocean research vessel that has a twist: it will sail the seas with a complement of aerial and ocean-going drones and no human crew.

    The Zhu Hai Yun, or Zhuhai Cloud, launched in Guangzhou after a year of construction. The 290-foot-long mothership can hit a top speed of 18 knots (about 20 miles per hour) and will carry 50 flying, surface, and submersible drones that launch and self-recover autonomously. 

    According to this blurb from the shipbuilder behind its construction, the Cloud will also be equipped with a variety of additional observational instruments "which can be deployed in batches in the target sea area, and carry out task-oriented adaptive networking to achieve three-dimensional view of specific targets." Most of the ship is an open deck where flying drones can land and be stored. The ship is also equipped with launch and recovery equipment for its aquatic craft. 

    Continue reading
  • Experts: AI should be recognized as inventors in patent law
    Plus: Police release deepfake of murdered teen in cold case, and more

    In-brief Governments around the world should pass intellectual property laws that grant rights to AI systems, two academics at the University of New South Wales in Australia argued.

    Alexandra George, and Toby Walsh, professors of law and AI, respectively, believe failing to recognize machines as inventors could have long-lasting impacts on economies and societies. 

    "If courts and governments decide that AI-made inventions cannot be patented, the implications could be huge," they wrote in a comment article published in Nature. "Funders and businesses would be less incentivized to pursue useful research using AI inventors when a return on their investment could be limited. Society could miss out on the development of worthwhile and life-saving inventions."

    Continue reading
  • Declassified and released: More secret files on US govt's emergency doomsday powers
    Nuke incoming? Quick break out the plans for rationing, censorship, property seizures, and more

    More papers describing the orders and messages the US President can issue in the event of apocalyptic crises, such as a devastating nuclear attack, have been declassified and released for all to see.

    These government files are part of a larger collection of records that discuss the nature, reach, and use of secret Presidential Emergency Action Documents: these are executive orders, announcements, and statements to Congress that are all ready to sign and send out as soon as a doomsday scenario occurs. PEADs are supposed to give America's commander-in-chief immediate extraordinary powers to overcome extraordinary events.

    PEADs have never been declassified or revealed before. They remain hush-hush, and their exact details are not publicly known.

    Continue reading
  • Stolen university credentials up for sale by Russian crooks, FBI warns
    Forget dark-web souks, thousands of these are already being traded on public bazaars

    Russian crooks are selling network credentials and virtual private network access for a "multitude" of US universities and colleges on criminal marketplaces, according to the FBI.

    According to a warning issued on Thursday, these stolen credentials sell for thousands of dollars on both dark web and public internet forums, and could lead to subsequent cyberattacks against individual employees or the schools themselves.

    "The exposure of usernames and passwords can lead to brute force credential stuffing computer network attacks, whereby attackers attempt logins across various internet sites or exploit them for subsequent cyber attacks as criminal actors take advantage of users recycling the same credentials across multiple accounts, internet sites, and services," the Feds' alert [PDF] said.

    Continue reading
  • Big Tech loves talking up privacy – while trying to kill privacy legislation
    Study claims Amazon, Apple, Google, Meta, Microsoft work to derail data rules

    Amazon, Apple, Google, Meta, and Microsoft often support privacy in public statements, but behind the scenes they've been working through some common organizations to weaken or kill privacy legislation in US states.

    That's according to a report this week from news non-profit The Markup, which said the corporations hire lobbyists from the same few groups and law firms to defang or drown state privacy bills.

    The report examined 31 states when state legislatures were considering privacy legislation and identified 445 lobbyists and lobbying firms working on behalf of Amazon, Apple, Google, Meta, and Microsoft, along with industry groups like TechNet and the State Privacy and Security Coalition.

    Continue reading
  • SEC probes Musk for not properly disclosing Twitter stake
    Meanwhile, social network's board rejects resignation of one its directors

    America's financial watchdog is investigating whether Elon Musk adequately disclosed his purchase of Twitter shares last month, just as his bid to take over the social media company hangs in the balance. 

    A letter [PDF] from the SEC addressed to the tech billionaire said he "[did] not appear" to have filed the proper form detailing his 9.2 percent stake in Twitter "required 10 days from the date of acquisition," and asked him to provide more information. Musk's shares made him one of Twitter's largest shareholders. The letter is dated April 4, and was shared this week by the regulator.

    Musk quickly moved to try and buy the whole company outright in a deal initially worth over $44 billion. Musk sold a chunk of his shares in Tesla worth $8.4 billion and bagged another $7.14 billion from investors to help finance the $21 billion he promised to put forward for the deal. The remaining $25.5 billion bill was secured via debt financing by Morgan Stanley, Bank of America, Barclays, and others. But the takeover is not going smoothly.

    Continue reading

Biting the hand that feeds IT © 1998–2022