Qualcomm 高通发布骁龙845移动平台：下代CPU&GPU，人工智能，新DSP和Modem【Anandtech】

本文地址：http://www.moepc.net/?post=3822

高通在此前的媒体活动中，终于发布了下代骁龙845处理器的信息。它将接替非常成功的前辈骁龙835，首先采用ARM的DynamIQ CPU丛集技术，这可能是近年来ARM SoC做出的最大改变。

CPU

骁龙835的 Kryo 280 Performance / Efficiency核心基于ARM的Built on ARM Cortex Technology授权，高通能让ARM对最新架构进行部分修改，变成自家专属的SoC架构 – 比如Kryo 280 Performance核心就基于Cortex-A73，Efficiency核心基于Cortex-A53 IP。

骁龙845则是首个采用ARM DynamIQ big.LITTLE CPU丛集技术的SoC。DynamIQ big.LITTLE能把不同架构的CPU核心放在同一丛集和缓存结构中。这是近年来ARM SoC做出的最大改变。

目前只有Cortex-A75和Cortex-A55支持DynamIQ，自然骁龙845的Kryo 385也是用的这俩。

此前的big.LITTLE都是不同丛集（每丛集最多4个CPU核心），也没有同一共享缓存，缓存一致性都要通过ARM CCI。

【DynamIQ介绍：

DynamIQ单个丛集最多8个CPU核心，最多支持32丛集 – 256核心，要是用上CCIX还能支持多芯片1000+个CPU核心。

ARM预想未来几年移动设备仍将维持8核的配置，之前的big.LITTLE的话只能4+4, 4大核+4小核，或者直接4小核+4小核。

有了DynamIQ，8个A75/A55核心可以随意配置：1+7，2+6，3+5，4+4

ARM认为1+7的架构，也就是1个A75大核+7个A55小核的配置非常适合中端市场。

相较八核A53，同样制程与频率下1+7的配置能提供241%的单线程性能，142%的多线程性能，芯片面积却只增长13%。

支持DynamIQ的CPU（目前只有A75/A55）的L2缓存均为私有，频率和CPU一致，由于L2距离核心更近了，延迟也降低了50%以上。

DynamIQ还新增了L3缓存，位于DynamIQ Shared Unit内部，16路组相连，可配置为1MB、2MB或4MB。技术上这块L3是pseudo-exclusive的，AMR称它非常接近完全exclusive，L3的几乎所有数据都不会出现在L2和L1里。】

骁龙845的Kryo 385 Gold 高性能核心频率为最高2.8GHz，比835的2.45GHz高了14%。由于Kryo 385用的是A75架构，相较A73的IPC提升在22-34%之间，意味着总体性能提升会达到39-52%。高通公布的数据为25-30%，比ARM的要保守。

Cortex-A75属于Sophia家族，与A73有许多共同之处。

同等频率下Cortex-A75比A73的性能要高22-34%，提升性能的空间更大。

整数性能提升22%，浮点性能提升33%

本文地址：http://www.moepc.net/?post=3822

Kryo 385 Sliver运行在1.8GHz，比835上的1.9GHz要低。小核心的频率一般定在与大核心能效曲线相交的位置，而且A55比A53性能高18%（整数）至38%（浮点/NEON），所以频率低了，性能反而增加了15%。

Cortex-A55，小核久违的一次更新。

A55依然是顺序执行，8级短管线。ARM称8级依然是最佳的sweetspot，因为从16/14nm到10nm，再到7nm频率都不会有多少提升。因此A55的频率和A53相近。

A55同频整数性能比A53高18%，浮点/NEON性能提升38%

单位频率功耗方面A55仅比A53高3%，性能增加的更多，所以能效也提升了15%。

DynamIQ DSU里的L3配置为2MB，大核/小核的L2应该是256/128KB，共3.5MB L2+L3缓存。

高通这次CPU之外还增加了一块新的系统缓存，大小为3MB。系统缓存类似于SoC互联缓存，供芯片上的所有模块共享 – 苹果的A系列SoC的L3也是这样。这有助于减少额外的内存传输，降低内存控制器和内存的耗电。高通称这块缓存能降低40-75%的内存访问带宽，非常显著。

GPU

骁龙845配备Adreno 630 GPU，一般百位数字的变化意味着GPU架构的换代。

高通一如往常地对GPU方面细节守口如瓶，只说性能会增加30%，能耗比提升30% – 相当于同样功耗下，Adreno 630性能比540高30%，这次提升也很不错。

DSP

DSP升级到了Hexagon 685，详细情况未知。高通称Hexagon 685性能更高，功耗更低。特别是人工智能和图像处理上有明显提升 – AI处理性能达到835的三倍。

传统的DSP架构对神经网络处理并没有优化，对845的性能我们还得拭目以待。苹果A11和麒麟 970这种SoC依然有优势，它们有独立NPU，还有图像处理管线，不需要交给DSP来处理；而845的DSP可能得同时干两件事。

骁龙 X20 Modem

高通最新的Modem一般会先以独立芯片的形式发布，后来再集成进自家高端处理器，这次也是一样。骁龙845集成了年初发布的X20 Modem。

X20支持到LTE UE Cat.18，支持5xCA，下行达到最高1.2Gbps（5x20MHz CA下行）

ISP

845的显示管线为VR做了升级，能驱动两个2400x2400p120显示屏。

视频编码能力也有改进，4K录制从30fps增加到60fps。高通称845支持Rec.2020宽色域，也就是HDR10 HEVC视频录制。

新的Spectra 280 ISP最显著的功能在于支持多帧降噪（Multi Frame Noise Reduction，MFNR），能够迅速捕捉多张图片，利用算法进行高质量降噪，画质要高于传统的单帧降噪。【相机上已经用了很久了…多张拍摄堆栈降噪】

【音频

音频Codec为Aqstic WCD934x

播放时动态范围130dB，总谐波失真加噪声（THD+N）-109dB

原生支持DSD播放（DSD64/DSD128）, PCM支持到384KHz/32bit

录制动态范围109dB，总谐波失真加噪声（THD+N）-103dB

采样最高192KHz/24bit

规格和835的Aqstic WCD9340/9341完全一致，应该是同款。】

10LPP制程

骁龙845采用三星的10LPP制程生产，从835的10LPE自然过渡。

三星上周刚宣布开始10LPP的大规模量产。同等频率下10LPP比10LPE功耗降低15%；同等功耗下10LPP比10LPE频率高10%。

2.8GHz的A73 vs 3GHz的A75

每瓦性能相同，A75性能更高

每瓦性能相同的情况下A75比A73性能高，说明A75的功耗也更高。高通这次还把频率从2.45提到2.8….

搭载835的设备单核峰值功耗能达到1.1W，845在换了架构的同时还提了频，这两个都会带来更多功耗。除非三星工艺提升够大，不然845的CPU功耗会高于835。

本文地址：http://www.moepc.net/?post=3822

原文：

Qualcomm Technologies, Inc., a subsidiary of Qualcomm Incorporated (NASDAQ:QCOM), has introduced the new Qualcomm® Snapdragon? 845 Mobile Platform. Thoughtfully designed with tech savvy consumers in mind, Snapdragon 845 utilizes Qualcomm Technologies’ industry leading wireless heterogenous compute expertise to design a platform for immersive multimedia experiences including eXtended reality (XR), on-device artificial intelligence (AI), lightning-fast connectivity, and introduces our new secure processing unit (SPU) delivering vault-like security for premium, flagship mobile devices.

Immerse: The Snapdragon 845 Mobile Platform was designed for consumers to capture cinema-grade videos and blur the lines between physical and virtual worlds. Snapdragon 845 introduces an integrated Qualcomm Spectra? 280 image signal processor (ISP) and Qualcomm® Adreno? 630 visual processing subsystem. These brand-new architectures bring high-performance, true-to-life cinematic video capture, along with superior photography to flagship mobile devices. Snapdragon 845 will be able to captures 64x more high-dynamic range color information for video capture and playback on Ultra HD Premium displays, compared to the previous generation ?a first in the mobile industry. This massive boost in color information includes 10-bit color depth for over one billion shades of colors that can be displayed to the wide Rec. 2020 gamut for amazing 4K/Ultra HD videos so your precious video memories can be viewed with a billion shades of brilliance.

In addition to advancing the video capture experience, the new Adreno 630 visual processing subsystem architecture will transform entertainment, education and social interaction, making them more immersive and intuitive. It is designed to deliver innovations for new XR experiences that span virtual, augmented and mixed reality. Snapdragon 845 is the first mobile platform to enable room-scale 6 degrees of freedom (6DoF) with simultaneous localization and mapping (SLAM)?for features such as wall-collision detection. Additionally, Snapdragon 845 introduces “Adreno foveation,” which substantially reduces power consumption, improves visual quality and boosts XR application performance, as compared to the previous generation.

AI: Snapdragon 845 is Qualcomm Technologies’ third-generation AI mobile platform, delivering 3x improvement in overall AI performance of the prior generation SoC ? transforming your mobile device into the ultimate personal assistant; simplifying how you take pictures and videos; enhancing your VR games, and making voice interaction natural. Snapdragon 845 improves voice-driven smart assistants with improved always-on keyword detection and ultra-low-power voice processing thanks to the performance from the Qualcomm Aqstic? audio codec (WCD9341) and low-power audio subsystem, so users can interact with their devices using their voice all day.

In addition to the existing support for Google’s TensorFlow and Facebook’s Caffe/Caffe2 frameworks, the Snapdragon Neural Processing Engine (NPE) SDK now supports Tensorflow Lite and the new Open Neural Network Exchange (ONNX), making it easy for developers to use their framework of choice, including Caffe2, CNTK and MxNet. Snapdragon 845 also supports Google’s Android NN API.

Secure: As security needs evolve, so do the security solutions within our mobile platforms. End-users demand enhanced privacy due to the significant growth of personal data being stored on the device. Similarly, payment companies are looking for more secure authentication mechanisms to increase reliability. The Snapdragon 845 introduces a hardware isolated subsystem called the secure processing unit (SPU), which is designed to add vault-like characteristics to existing layers of Qualcomm Technologies’ mobile security solutions. Doing so makes it possible for improved biometrics security used for authentication, as well as user or application data key management used to encrypt critical information.

Connect: The Snapdragon 845 features our most advanced suite of wireless technologies ever in a mobile platform, with cutting edge LTE, Wi-Fi, and Bluetooth features. The Snapdragon 845 integrates Qualcomm Technologies’ second-generation Gigabit LTE solution ? the Snapdragon X20 LTE modem. Its lightning-fast connection speeds allow users to enjoy immersive XR experiences in more places, download a 3GB movie in less than 3 minutes, just before boarding a flight and access large files or apps in the cloud as fast as those stored in their phones’ memory. The Snapdragon X20 modem supports an expanded range of technology and frequency band configurations across licensed, unlicensed and shared radio spectrum ? all designed to accelerate global availability of Gigabit LTE as operators prepare for 5G. The modem supports LTE Category 18 peak download speeds of 1.2 Gbps, up to 5x carrier aggregation, License Assisted Access (LAA), Dual SIM-Dual VoLTE as well as 4×4 MIMO on up to 3 aggregated carriers.

Snapdragon 845 also includes diversity-enhanced 60GHz 802.11ad Wi-Fi for more robust multi-gigabit coverage at speeds up to 4.6 Gbps, and integrated 802.11ac Wi-Fi with advanced features that provide up to 16X faster connection setup, simultaneous dual-band support for an ever-expanding set of applications and 30 percent more capacity utilization on carrier Wi-Fi networks, compared to the previous generation. The platform’s proprietary enhancements to Bluetooth 5 allow users to broadcast audio simultaneously to multiple wireless speakers, smartphones or other devices and are designed to reduce battery consumption of wireless earbuds by up to 50 percent compared to the previous generation.

Perform:  Through heterogenous computing, the Snapdragon 845’s new architectures are being built to transform the user experience while providing significant improvements in performance and battery life. The new camera and visual processing architectures will help Snapdragon 845 deliver up to 30 percent power reduction for video capture, games and XR applications compared to the previous generation. Graphics performance and power efficiencies will also garner up to a 30 percent improvement as a result of the new Adreno 630, compared to the previous generation. The new Qualcomm® Kryo? 385 architecture, built on Arm® Cortex? technology, will see up to 25 percent performance uplift across gaming, application launch times, and performance intensive applications compared to the previous generation.

“As leaders in mobile technology, we will transform the mobile experience with comprehensive advancements in visual processing, AI, security and connectivity,” said Alex Katouzian, senior vice president and general manager, mobile, Qualcomm Technologies, Inc. “The Snapdragon 845 Mobile Platform is the next horizon of innovation and is going to transform the way people use their mobile devices to make their lives better.”

The Snapdragon 845 Mobile Platform is currently sampling to customers and is expected to begin shipping in commercial devices in early 2018. Snapdragon 845 will power devices such as smartphones, XR headsets and always connected PCs. For more information on the Snapdragon 845, please visit Qualcomm’s site at www.qualcomm.com/snapdragon.

The Snapdragon 845 Mobile Platform features include:

Qualcomm Spectra 280 ISP

-Ultra HD premium capture

-Qualcomm Spectra Module Program, featuring Active Depth Sensing -MCTF video capture

-Multi-frame noise reduction

-High performance capture up to 16MP @60FPS

-Slow motion video capture (720p @480 fps)

-ImMotion computational photography

Adreno 630 Visual Processing Subsystem

-30% improved graphics/video rendering and power reduction compared to previous generation

-Room-scale 6 DoF with SLAM

-Adreno foveation, featuring tile rendering, eye tracking, multiView rendering, fine grain preemption -2K x 2K @ 120Hz, for 2.5x faster display throughput

-Improved 6DoF with hand-tracking and controller support

Qualcomm® Hexagon? 685 DSP

-3rd Generation Hexagon Vector DSP (HVX) for AI and imaging

-3rd Generation Qualcomm All-Ways AwareTM Sensor Hub

? Hexagon scalar DSP for audio

Snapdragon X20 LTE Modem

? Support for 1.2 Gbps Gigabit LTE Category 18

? License Assisted Access (LAA)

? Citizens Broadband Radio Service (CBRS) shared radio spectrum

? Dual SIM-Dual VoLTE (DSDV)

Connectivity

Multigigabit 11ad Wi-Fi with diversity module

Integrated 2×2 11ac Wi-Fi with Dual Band Simultaneous (DBS) support

11k/r/v: Carrier Wi-Fi enhanced mobility, fast acquisition and congestion mitigation

Bluetooth 5 with proprietary enhancements for ultra-low power wireless ear bud support and direct audio broadcast to multiple devices

Secure Processing Unit

? Biometric authentication (fingerprint, iris, voice, face)

? User and app data protection

? Integrated use-cases such as integrated SIM, Payments, and more

Qualcomm Aqstic Audio

Qualcomm Aqstic audio codec(WCD934x):

Playback:

Dynamic range: 130dB, THD+N: -109dB

Native DSD support (DSD64/DSD128), PCM up to 384kHz/32bit

Low power voice activation: 0.65mA

Record:

Dynamic range: 109dB, THD+N: -103dB

Sampling: Up to 192kHz/24bit

Qualcomm® Quick Charge? 4+

Kryo 385 CPU

-Four performance cores up to 2.8GHz (25 percent performance uplift compared to previous generation)

? Four efficiency cores up to 1.8GHz

-2MB shared L3 cache (new)

-3MB system cache (new)

10-nanometer (nm) LPP FinFET process technology

本文地址：http://www.moepc.net/?post=3822
via：https://www.anandtech.com/show/12114/qualcomm-announces-snapdragon-845-soc

https://www.anandtech.com/show/11441/dynamiq-and-arms-new-cpus-cortex-a75-a55/

https://www.qualcomm.com/products/features/aqstic
原作者：Andrei Frumusanu，Matt Humrick，Qualcomm
MOEPC.NET编译及整理，转载请注明出处。