ARM Cortex-A76
{{Short description|CPU released in 2018}}
{{Infobox CPU
| name = ARM Cortex-A76
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| designfirm = ARM Holdings
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| slowest =
| fastest = 3.0 GHz in phones and 3.3 GHz in tablets/laptops
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| fsb-slowest = 100
| fsb-fastest = 104
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| address-width = 40-bit
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| l1cache = {{Nowrap|128 KiB}} {{Small|({{Nowrap|64 KiB}} I-cache with parity, {{Nowrap|64 KiB}} D-cache)}} per core
| l2cache = {{Nowrap|128–512 KiB}} per core
| l3cache = {{Nowrap|512 KiB–4 MiB}} {{Small|(optional)}}
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| microarch = ARM Cortex-A76
| arch = ARMv8-A: A64, A32, and T32 {{Small|(at the EL0 only)}}
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| extensions = ARMv8.1-A, ARMv8.2-A, Cryptography, RAS, ARMv8.3-A LDAPR instructions, ARMv8.4-A dot product
| transistors =
| numcores = 1–4 per cluster
| gpu =
| co-processor = ARM Cortex-A55 {{Small|(optional)}}
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| pcode1 = Enyo
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| variant = Arm Neoverse N1
| predecessor = ARM Cortex-A75
ARM Cortex-A73
ARM Cortex-A72
| successor = ARM Cortex-A77
}}
The ARM Cortex-A76 is a central processing unit implementing the ARMv8.2-A 64-bit instruction set designed by ARM Holdings' Austin design centre. ARM states a 25% and 35% increase in integer and floating point performance, respectively, over a Cortex-A75 of the previous generation.{{cite news |last1=Frumusanu |first1=Andrei |title=Arm Cortex-A76 CPU Unveiled |url=https://www.anandtech.com/show/12785/arm-cortex-a76-cpu-unveiled-7nm-powerhouse |accessdate=1 June 2018 |publisher=Anandtech |date=31 May 2018}}
Design
The Cortex-A76 serves as the successor of the ARM Cortex-A73 and ARM Cortex-A75, though based on a clean sheet design.
The Cortex-A76 frontend is a 4-wide decode out-of-order superscalar design. It can fetch 4 instructions per cycle. And{{clarify|date=September 2020}} rename and dispatch 4 Mops, and 8 μops per cycle. The out-of-order window size is 128 entries. The backend is 8 execution ports{{clarify|date=September 2020}} with a pipeline depth of 13 stages and the execution latencies of 11 stages.{{Cite web|date=2019-05-26|title=Arm Unveils Cortex-A77, Emphasizes Single-Thread Performance|url=https://fuse.wikichip.org/news/2339/arm-unveils-cortex-a77-emphasizes-single-thread-performance/|access-date=2020-06-18|website=WikiChip Fuse|language=en-US}}
The core supports unprivileged 32-bit applications, but privileged applications must utilize the 64-bit ARMv8-A ISA.{{cite news |last1=Williams |first1=Chris |title=Arm emits Cortex-A76 – its first 64-bit-only CPU core (in kernel mode) |url=https://www.theregister.co.uk/2018/05/31/arm_cortex_a76/ |accessdate=1 June 2018 |publisher=The Register |date=31 May 2018}} It also supports Load acquire (LDAPR) instructions (ARMv8.3-A), Dot Product instructions (ARMv8.4-A), PSTATE Speculative Store Bypass Safe (SSBS) bit and the speculation barriers (CSDB, SSBB, PSSBB) instructions (ARMv8.5-A).{{Cite web|url=http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.100798_0300_00_en/index.html|title=ARM documentation set for Cortex-A76|website=infocenter.arm.com|access-date=2019-06-15}}
Memory bandwidth increased 90% relative to the A75.{{cite news |last1=Armasu |first1=Lucian |title=Arm's Cortex-A76 Could Be The First True Challenger To x86 Chips On Laptops |url=https://www.tomshardware.com/news/cortex-76-high-laptop-performance,37158.html |accessdate=1 June 2018 |publisher=Tom's Hardware |date=31 May 2018}}{{cite news |last1=Triggs |first1=Robert |title=Arm Cortex-A76 CPU deep dive |url=https://www.androidauthority.com/cortex-a76-deep-dive-870896/ |accessdate=1 June 2018 |publisher=Android Authority |date=31 May 2018}} According to ARM, the A76 is expected to offer twice the performance of an A73 and is targeted beyond mobile workloads. The performance is targeted at "laptop class", including Windows 10 devices,{{cite news |last1=Hruska |first1=Joel |title=ARM's New Cortex-A76 SoC Targets Windows Laptop Market |url=https://www.extremetech.com/mobile/270362-arm-cortex-a76-targets-laptop-market |accessdate=1 June 2018 |publisher=Extreme Tech |date=31 May 2018}} competitive with Intel's Kaby Lake.{{cite news |last1=Bright |first1=Peter |title=ARM promises laptop-level performance in 2019 |url=https://arstechnica.com/gadgets/2018/06/arm-promises-laptop-level-performance-in-2019/ |accessdate=1 June 2018 |publisher=Ars Technica |date=1 June 2018}}
The Cortex-A76 support ARM's DynamIQ technology, expected to be used as high-performance cores when used in combination with Cortex-A55 power-efficient cores.
Licensing
The Cortex-A76 is available as a SIP core to licensees, and its design makes it suitable for integration with other SIP cores (e.g. GPU, display controller, DSP, image processor, etc.) into one die constituting a system on a chip (SoC).
Usage
The Cortex-A76 was first used in the HiSilicon Kirin 980.{{Cite web|last=Frumusanu|first=Andrei|title=HiSilicon Announces The Kirin 980: First A76, G76 on 7nm|url=https://www.anandtech.com/show/13298/hisilicon-announces-the-kirin-980-first-a76-g76-on-7nm|access-date=2020-11-13|website=www.anandtech.com}}
ARM has also collaborated with Qualcomm for a semi-custom version of the Cortex-A76, used within their high-end Kryo 495 (Snapdragon 8cx)/Kryo 485 (Snapdragon 855 and 855 Plus), and also in their mid-range Kryo 460 (Snapdragon 675) and Kryo 470 (Snapdragon 730) CPUs. One of the modifications Qualcomm made was increasing reorder buffer to increase the out-of-order window size.{{Cite web|url=https://www.anandtech.com/show/14384/arm-announces-cortexa77-cpu-ip|title=Arm's New Cortex-A77 CPU Micro-architecture: Evolving Performance|last=Frumusanu|first=Andrei|website=www.anandtech.com|access-date=2019-06-16}}
It is also used in the Exynos 990 and Exynos Auto V9,{{Cite web|title=Exynos 990 Mobile Processor: Specs, Features {{!}} Samsung Exynos|url=https://www.samsung.com/semiconductor/minisite/exynos/products/mobileprocessor/exynos-990/|access-date=2020-06-18|website=Samsung Semiconductor|language=en}} the MediaTek Helio G90/G90T/G95/G99 and Dimensity 800 and Dimensity 820, and the HiSilicon Kirin 985 5G and Kirin 990 4G/990 5G/990E 5G.{{Cite web|last=MediaTek|date=2020-06-18|title=MediaTek Helio G90 Series|url=https://www.mediatek.com/products/smartphones/mediatek-helio-g90-series|access-date=2020-06-18|website=MediaTek|language=en}}{{Cite web|last=MediaTek|date=2020-06-18|title=MediaTek Dimensity 800|url=https://www.mediatek.com/products/smartphones/dimensity-800|access-date=2020-06-18|website=MediaTek|language=en}}{{Cite web|last=MediaTek|date=2020-06-18|title=MediaTek Dimensity 820|url=https://www.mediatek.com/products/smartphones/dimensity-820|access-date=2020-06-18|website=MediaTek|language=en}}
The Cortex-A76 can be found in Snapdragon 855 as Big-core.
The Cortex-A76 is used as Big-core in Intel Agilex D-series SoC FPGA devices.{{Cite web|title=Intel Agilex D-Series FPGA White Paper|author=Mark van der Zalm|url=https://www.intel.com/content/www/us/en/products/docs/programmable/agilex-d-series-fpga-whitepaper.html|website=Intel|access-date=2022-10-20}}
In 2020 Cortex-A76 was used in Rockchip RK3588 and RK3588s.
In September 2023, the Raspberry Pi 5 was introduced with a Broadcom BCM2712 quad-core Arm Cortex-A76 processor with a clock speed of 2.4 GHz.{{Cite web|title=Introducing: Raspberry Pi 5!|author=Eben Upton|url=https://www.raspberrypi.com/news/introducing-raspberry-pi-5/|website=Raspberry Pi|access-date=2023-10-21}}
See also
- ARM Cortex-A75, predecessor
- ARM Cortex-A77, successor
- Comparison of ARMv8-A cores, ARMv8 family