The first is a new Cortex-A77 CPU, which will drive a 20 percent uplift in IPC performance compared to the Cortex-A76 used in the Snapdragon 855, while memory bandwidth has increased by 15 percent. Arm says that it has also managed to improve machine learning performance over the past two generations of high-end Cortex CPU designs by 35x.
Like the Cortex-A76 before it, Cortex-A77 designs will still be built on the 7nm process node and will be serve as the "big" counterpart in Arm's big.LITTLE DynamIQ clusters. Cortex-A77 is based on the Armv8.2 architecture with support for both AArch32 and AArch64. The L1 branch target buffer (BTB) is now 4x larger, while the L2 BTB is now 33 percent larger. In addition, here are some other optimizations that ARM has made along the way:
- Integer execution bandwidth has increased by 50 percent
- Dispatch bandwidth has increased 50 percent (6 instructions/cycle)
- Out-of-order windows see has increased 25 percent (160 instructions)
- AES encryption pipeline has been doubled
- Dedicated load-store issue bandwidth has doubled
The other big new component is the Mali-G77 GPU, which is the first to use Arm's new Valhall architecture. Compared to the current-generation Mali-G76, ARM is targeting a 40 percent uplift in peak graphics performance while delivering an overall 30 percent improvement in energy efficiency.
Given that we didn’t see the first Snapdragon 855 and Exynos 9820 SoCs hit the market until 2020, it’s likely that we won’t see [rumored] Snapdragon 865 and Exynos 9830 SoCs with Cortex-A77/Mali-G77 until 2020. Huawei is typically a little quicker out of the gate with its releases, but with Arm cutting is ties with the company, we don’t know how that will affect the its processor roadmap.