多核心CPU分配器充分发挥处理器性能
esxiwindowscpu多核的设置原理详细说明
esxiwindowscpu多核的设置原理详细说明物理cpu（即插槽）：真实的⼀个CPU；⽐如 2core：⼀个cpu有多少核；⽐如 8hyper threading：超线程技术，即再虚拟个核出来。
所以虚拟软件vmware，esxi最终会算出多少个逻辑cpu：物理cpu(slot) * cores * 2 = 2*8*2=24linux对物理cpu或者slot没有限制。
win10 专业版最多运⾏2个slot或者物理cpu。
在win10上，如果你的esxi虚拟出 vCpu = 16个，由于最多运⾏两个插槽，即2个物理cpu。
那需要配置它的每个cpu核⼼是8核。
这样正好有2 slot。
Setting the Number of Cores per CPU in a Virtual Machine: A How-to GuideWhen creating virtual machines, you should configure processor settings for them. With hardware virtualization, you can select the number of virtual processors for a virtual machine and set the number of sockets and processor cores. How many cores per CPU should you select for optimal performance? Which configuration is better: setting fewer processors with more CPU cores or setting more processors with fewer CPU cores? This blog post explains the main principles of processor configuration for VMware virtual machines. TerminologyFirst of all, let’s go over the definitions of the terms you should know when configuring CPU settings for to help you understand the working principle. Knowing what each term means allows you to avoid confusion about the number of cores per CPU, CPU cores per socket, and the number of CPU cores vs speed.A CPU Socket is a physical connector on the motherboard to which a single physical CPU is connected. A motherboard has at least one CPU socket. Server motherboards usually have multiple CPU sockets that support multiple multicore processors. CPU sockets are standardized for different processor series. Intel and AMD use different CPU sockets for their processor families.A CPU (central processing unit, microprocessor chip, or processor) is a computer component. It is the electronic circuitry with transistors that is connected to a socket. A CPU executes instructions to perform calculations, run applications, and complete tasks. When the clock speed of processors came close to the heat barrier, manufacturers changed the architecture of processors and started producing processors with multiple CPU cores. To avoid confusion between physical processors and logical processors or processor cores, some vendors refer to a physical processor as a socket.A CPU core is the part of a processor containing the L1 cache. The CPU core performs computational tasks independently without interacting with other cores and external components of a “big” processor that are shared among cores. Basically, a core can be considered as a small processor built into the main processor that is connected to a socket. Applications should support parallel computations to use multicore processors rationally.Hyper-threading is a technology developed by Intel engineers to bring parallel computation to processors that have one processor core. The debut of hyper-threading was in 2002 when the Pentium 4 HT processor was released and positioned for desktop computers. An operating system detects a single-core processor with hyper-threading as a processor with two logical cores (not physical cores). Similarly, a four-core processor with hyper-threading appears to an OS as a processor with 8 cores. The more threads run on each core, the more tasks can be done in parallel. Modern Intel processors have both multiple cores and hyper-threading. Hyper-threading is usually enabled by default and can be enabled or disabled in BIOS. AMD simultaneous multi-threading (SMT) is the analog of hyper-threading for AMD processors.A vCPU is a virtual processor that is configured as a virtual device in the virtual hardware settings of a VM. A virtual processor can be configured to use multiple CPU cores. A vCPU is connected to a virtual socket.CPU overcommitment is the situation when you provision more logical processors (CPU cores) of a physical host to VMs residing on the host than the total number of logical processors on the host.NUMA (non-uniform memory access) is a computer memory design used in multiprocessor computers. The idea is to provide separate memory for each processor (unlike UMA, where all processors access shared memory through a bus). At the same time, a processor can access memory that belongs to other processors by using a shared bus (all processors access all memory on the computer). A CPU has a performance advantage of accessing own local memory faster than other memory on a multiprocessor computer.These basic architectures are mixed in modern multiprocessor computers. Processors are grouped on a multicore CPU package or node. Processors that belong to the same node share access to memory modules as with the UMA architecture. Also, processors can access memory from the remote node via a shared interconnect. Processors do so for the NUMA architecture but with slower performance. This memory access is performed through the CPU that owns that memory rather than directly.NUMA nodes are CPU/Memory couples that consist of a CPU socket and the closest memory modules. NUMA is usually configured in BIOS as the node interleaving or interleaved memory setting.An example. An ESXi host has two sockets (two CPUs) and 256 GB of RAM. Each CPU has 6 processor cores. This server contains two NUMA nodes. Each NUMA node has 1 CPU socket (one CPU), 6 Cores, and 128 GB of RAM.always tries to allocate memory for a VM from a native (home) NUMA node. A home node can be changed automatically if there are changes in VM loads and ESXi server loads.Virtual NUMA (vNUMA) is the analog of NUMA for VMware virtual machines. A vNUMA consumes hardware resources of more than one physical NUMA node to provide optimal performance. The vNUMA technology exposes the NUMA topology to a guest operating system. As a result, the guest OS is aware of the underlying NUMA topology for the most efficient use. The virtual hardware version of a VM must be 8 or higher to use vNUMA. Handling of vNUMA was significantly improved in VMware vSphere 6.5, and this feature is no longer controlled by the CPU cores per socket value in the VM configuration. By default, vNUMA is enabled for VMs that have more than 8 logical processors (vCPUs). You can enable vNUMA manually for a VM by editing the VMX configuration file of the VM and adding theline numa.vcpu.min=X, where X is the number of vCPUs for the virtual machine.CalculationsLet’s find out how to calculate the number of physical CPU cores, logical CPU cores, and other parameters on a server.The total number of physical CPU cores on a host machine is calculated with the formula:(The number of Processor Sockets) x (The number of cores/processor) = The number of physical processor cores*Processor sockets only with installed processors must be considered.If hyper-threading is supported, calculate the number of logical processor cores by using the formula:(The number of physical processor cores) x (2 threads/physical processor) = the number of logical processorsFinally, use a single formula to calculate available processor resources that can be assigned to VMs:(CPU sockets) x (CPU cores) x (threads)For example, if you have a server with two processors with each having 4 cores and supporting hyper-threading, then the total number of logical processors that can be assigned to VMs is2(CPUs) x 4(cores) x 2(HT) = 16 logical processorsOne logical processor can be assigned as one processor or one CPU core for a VM in VM settings.As for virtual machines, due to hardware emulation features, they can use multiple processors and CPU cores in their configuration for operation. One physical CPU core can be configured as a virtual CPU or a virtual CPU core for a VM.The total amount of clock cycles available for a VM is calculated as:(The number of logical sockets) x (The clock speed of the CPU)For example, if you configure a VM to use 2 vCPUs with 2 cores when you have a physical processor whose clock speed is 3.0 GHz, then the total clock speed is 2x2x3=12 GHz. If CPU overcommitment is used on an ESXi host, the available frequency for a VM can be less than calculated if VMs perform CPU-intensive tasks.LimitationsThe maximum number of virtual processor sockets assigned to a VM is 128. If you want to assign more than 128 virtual processors, configure a VM to use multicore processors.The maximum number of processor cores that can be assigned to a single VM is 768 in vSphere 7.0 Update 1. A virtual machine cannot use more CPU cores than the number of logical processor cores on a physical machine.CPU hot add. If a VM has 128 vCPUs or less than 128 vCPUs, then you cannot use the CPU hot add feature for this VM and edit the CPU configuration of a VM while a VM is in the running state.OS CPU restrictions. If an operating system has a limit on the number of processors, and you assign more virtual processors for a VM, the additional processors are not identified and used by a guest OS. Limits can be caused by OS technical design and OS licensing restrictions. Note that there are operating systems that are licensed per-socket and per CPU core (for example, ).CPU support limits for some operating systems:Windows 10 Pro – 2 CPUsWindows 10 Home – 1 CPUWindows 10 Workstation – 4 CPUsWindows Server 2019 Standard/Datacenter – 64 CPUsWindows XP Pro x64 – 2 CPUsWindows 7 Pro/Ultimate/Enterprise - 2 CPUsWindows Server 2003 Datacenter – 64 CPUsConfiguration RecommendationsFor older vSphere versions, I recommend using sockets over cores in VM configuration. At first, you might not see a significant difference in CPU sockets or CPU cores in VM configuration for VM performance. Be aware of some configuration features. Remember about NUMA and vNUMA when you consider setting multiple virtual processors (sockets) for a VM to have optimal performance.If vNUMA is not configured automatically, mirror the NUMA topology of a physical server. Here are some recommendations for VMs in VMware vSphere 6.5 and later:When you define the number of logical processors (vCPUs) for a VM, prefer the cores-per-socket configuration. Continue until the count exceeds the number of CPU cores on a single NUMA node on the ESXi server. Use the same logic until you exceed the amount of memory that is available on a single NUMA node of your physical ESXi server.Sometimes, the number of logical processors for your VM configuration is more than the number of physical CPU cores on a single NUMA node, or the amount of RAM is higher than the total amount of memory available for a single NUMA node. Consider dividing the count of logical processors (vCPUs) across the minimum number of NUMA nodes for optimal performance.Don’t set an odd number of vCPUs if the CPU count or amount of memory exceeds the number of CPU cores. The same applies in case memory exceeds the amount of memory for a single NUMA node on a physical server.Don’t create a VM that has a number of vCPUs larger than the count of physical processor cores on your physical host.If you cannot disable vNUMA due to your requirements, don’t enable the vCPU Hot-Add feature.If vNUMA is enabled in vSphere prior to version 6.5, and you have defined the number of logical processors (vCPUs) for a VM, select the number of virtual sockets for a VM while keeping the cores-per-socket amount equal to 1 (that is the default value). This is because the one-core-per-socket configuration enables vNUMA to select the best vNUMA topology to the guest OS automatically. This automatic configuration is optimal on the underlying physical topology of the server. If vNUMA is enabled, and you’re using the same number of logical processors (vCPUs) but increase the number of virtual CPU cores and reduce the number of virtual sockets by the same amount, then vNUMA cannot set the best NUMA configuration for a VM. As a result, VM performance is affected and can degrade.If a guest operating system and other software installed on a VM are licensed on a per-processor basis, configure a VM to use fewer processors with more CPU cores. For example, Windows Server 2012 R2 is licensed per socket, and Windows Server 2016 is licensed on a per-core basis.If you use CPU overcommitment in the configuration of your VMware virtual machines, keep in mind these values: 1:1 to 3:1 – There should be no problems in running VMs3:1 to 5:1 – Performance degradation is observed6:1 – Prepare for problems caused by significant performance degradationCPU overcommitment with normal values can be used in test and dev environments without risks.Configuration of VMs on ESXi HostsFirst of all, determine how many logical processors (Total number of CPUs) of your physical host are needed for a virtual machine for proper work with sufficient performance. Then define how many virtual sockets with processors (Number of Sockets in vSphere Client) and how many CPU cores (Cores per Socket) you should set for a VM keeping in mind previous recommendations and limitations. The table below can help you select the needed configuration.If you need to assign more than 8 logical processors for a VM, the logic remains the same. To calculate the number of logical CPUs in , multiply the number of sockets by the number of cores. For example, if you need to configure a VM to use 2-processor sockets, each has 2 CPU cores, then the total number of logical CPUs is 2*2=4. It means that you should select 4 CPUs in the virtual hardware options of the VM in vSphere Client to apply this configuration.Let me explain how to configure CPU options for a VM in VMware vSphere Client. Enter the IP address of your in a web browser, and open VMware vSphere Client. In the navigator, open Hosts and Clusters, and select the needed virtual machine that you want to configure. Make sure that the VM is powered off to be able to change CPU configuration.Right-click the VM, and in the context menu, hit Edit Settings to open virtual machine settings.Expand the CPU section in the Virtual Hardware tab of the Edit Settings window.CPU. Click the drop-down menu in the CPU string, and select the total number of needed logical processors for this VM. In this example, Iselect 4 logical processors for the Ubuntu VM (blog-Ubuntu1).Cores per Socket. In this string, click the drop-down menu, and select the needed number of cores for each virtual socket (processor). CPU Hot Plug. If you want to use this feature, select the Enable CPU Hot Add checkbox. Remember limitations and requirements. Reservation. Select the guaranteed minimum allocation of CPU clock speed (frequency, MHz, or GHz) for a virtual machine on an ESXi host or cluster.Limit. Select the maximum CPU clock speed for a VM processor. This frequency is the maximum frequency for a virtual machine, even if this VM is the only VM running on the ESXi host or cluster with more free processor resources. The set limit is true for all virtual processors of a VM. If a VM has 2 single-core processors, and the limit is 1000 MHz, then both virtual processors work with a total clock speed of one million cycles per second (500 MHz for each core).Shares. This parameter defines the priority of resource consumption by virtual machines (Low, Normal, High, Custom) on an ESXi host or resource pool. Unlike Reservation and Limit parameters, the Shares parameter is applied for a VM only if there is a lack of CPU resources within an ESXi host, resource pool, or DRS cluster.Available options for the Shares parameter:Low – 500 shares per a virtual processorNormal - 1000 shares per a virtual processorHigh - 2000 shares per a virtual processorCustom – set a custom valueThe higher the Shares value is, the higher the amount of CPU resources provisioned for a VM within an ESXi host or a resource pool. Hardware virtualization. Select this checkbox to enable . This option is useful if you want to run a VM inside a VM for testing or educational purposes.Performance counters. This feature is used to allow an application installed within the virtual machine to be debugged and optimized after measuring CPU performance.Scheduling Affinity. This option is used to assign a VM to a specific processor. The entered value can be like this: “0, 2, 4-7”.I/O MMU. This feature allows VMs to have direct access to hardware input/output devices such as storage controllers, network cards, graphic cards (rather than using emulated or paravirtualized devices). I/O MMU is also called Intel Virtualization Technology for Directed I/O (Intel VT-d) and AMD I/O Virtualization (AMD-V). I/O MMU is disabled by default. Using this option is deprecated in vSphere 7.0. If I/O MMU is enabled for a VM, the VM cannot be migrated with and is not compatible with snapshots, memory overcommit, suspended VM state, physical NIC sharing, and .If you use a standalone ESXi host and use VMware Host Client to configure VMs in a web browser, the configuration principle is the same as for VMware vSphere Client.If you connect to vCenter Server or ESXi host in and open VM settings of a vSphere VM, you can edit the basic configuration of virtual processors. Click VM > Settings, select the Hardware tab, and click Processors. On the following screenshot, you see processor configuration for the same Ubuntu VM that was configured before in vSphere Client. In the graphical user interface (GUI) of VMware Workstation, you should select the number of virtual processors (sockets) and the number of cores per processor. The number of total processor cores (logical cores of physical processors on an ESXi host or cluster) is calculated and displayed below automatically. In the interface of vSphere Client, you set the number of total processor cores (the CPUs option), select the number of cores per processor, and then the number of virtual sockets is calculated and displayed.Configuring VM Processors in PowerCLIIf you prefer using the command-line interface to configure components of VMware vSphere, use to edit the CPU configuration of VMs. Let’s find out how to edit VM CPU configuration for a VM which name is Ubuntu 19 in Power CLI. The commands are used for VMs that are powered off.To configure a VM to use two single-core virtual processors (two virtual sockets are used), use the command:get-VM -name Ubuntu19 | set-VM -NumCpu 2Enter another number if you want to set another number of processors (sockets) to a VM.In the following example, you see how to configure a VM to use two dual-core virtual processors (2 sockets are used):$VM=Get-VM -Name Ubuntu19$VMSpec=New-Object -Type VMware.Vim.VirtualMachineConfigSpec -Property @{ "NumCoresPerSocket" = 2}$VM.ExtensionData.ReconfigVM_Task($VMSpec)$VM | Set-VM -NumCPU 2Once a new CPU configuration is applied to the virtual machine, this configuration is saved in the VMX configuration file of the VM. In my case, I check the Ubuntu19.vmx file located in the VM directory on the datastore (/vmfs/volumes/datastore2/Ubuntu19/). Lines with new CPU configuration are located at the end of the VMX file.numvcpus = "2"cpuid.coresPerSocket = "2"If you need to reduce the number of processors (sockets) for a VM, use the same command as shown before with less quantity. For example, to set one processor (socket) for a VM, use this command:get-VM -name Ubuntu19 | set-VM -NumCpu 1The main advantage of using Power CLI is the ability to configure multiple VMs in bulk. is important and convenient if the number of virtual machines to configure is high. Use VMware cmdlets and syntax of Microsoft PowerShell to create scripts.ConclusionThis blog post has covered the configuration of virtual processors for VMware vSphere VMs. Virtual processors for virtual machines are configured in VMware vSphere Client and in Power CLI. The performance of applications running on a VM depends on the correct CPU and memory configuration. In VMware vSphere 6.5 and later versions, set more cores in CPU for virtual machines and use the CPU cores per socket approach. If you use vSphere versions older than vSphere 6.5, configure the number of sockets without increasing the number of CPU cores for a VM due to different behavior of vNUMA in newer and older vSphere versions. Take into account the licensing model of software you need to install on a VM. If the software is licensed on using a per CPU model, configure more cores per CPU in VM settings. When using virtual machines in VMware vSphere, don’t forget about . Use NAKIVO Backup & Replication to back up your virtual machines, including VMs that have multiple cores per CPU. Regular backup helps you protect your data and recover the data in case of a .5(100%)4votes。
华硕B85M-G主板说明书C8146
B85M-G
用戶手冊
Motherboard
C8146
第一版（V1） 2013 年 5 月
版權說明 ©ASUSTeK Computer Inc. All rights reserved. 華碩電腦股份有限公司保留所有權利。
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(1) for free by downloading it from /download; or (2) for the cost of reproduction and shipment, which is dependent on the preferred carrier and the location where you want to have it shipped to, by sending a request to:
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中国机器学习白皮书
中国机器学习白皮书中国人工智能学会二○一五年十一月《中国人工智能系列白皮书》编委会主任：李德毅执行主任：王国胤副主任：杨放春谭铁牛黄河燕焦李成马少平刘宏蒋昌俊任福继杨强委员：陈杰董振江杜军平桂卫华韩力群何清黄心汉贾英民李斌刘民刘成林刘增良鲁华祥马华东马世龙苗夺谦朴松昊乔俊飞任友群孙富春孙长银王轩王飞跃王捍贫王万森王卫宁王小捷王亚杰王志良吴朝晖吴晓蓓夏桂华严新平杨春燕余凯余有成张学工赵春江周志华祝烈煌庄越挺《中国机器学习白皮书》编写组组长：陈松灿高阳组员：黄圣君李武军薛晖俞扬余志文詹德川詹志辉张利军张敏灵庄福振目录第1章引言 (1)第2章主流机器学习技术进展 (3)2.1 度量学习 (3)2.2 多核学习 (7)2.3 多视图学习 (10)2.4 集成学习 (14)2.5 主动学习 (18)2.6 强化学习 (22)第3章新兴机器学习技术选介 (27)3.1 迁移学习 (27)3.2 深度学习 (31)3.3 统计关系学习 (34)3.4 演化学习 (36)第4章大数据时代的机器学习 (41)4.1 并行机器学习 (41)4.2 哈希学习 (46)4.3 在线学习 (48)第5章结束语 (52)第1章引言“机器学习”（Machine Learning）是人工智能的核心研究领域之一，其最初的研究动机是为了让计算机系统具有人的学习能力以便实现人工智能[1]。
机器学习领域奠基人之一、美国工程院院士T. Mitchell 教授在其经典教材《Machine Learning》中所给出的机器学习经典定义为“利用经验来改善计算机系统自身的性能”[2]。
一般而言，经验对应于历史数据（如互联网数据、科学实验数据等），系统对应于数据模型（如决策树、支持向量机等），而性能则是模型对新数据的处理能力（如分类和预测性能等）。
因此，机器学习的根本任务是数据的智能分析与建模。
随着信息技术不断向网络化、低成本方向发展，人们在社会生活、科学研究等各个领域中的数据正以前所未有的速度产生并被广泛收集、存储。
神舟电脑 笔记本电脑 说明书
1-3
系统概观
俯视图
7. 静音模式启动钮 当您按下这个按钮，系统即将自动降低系统的用电 1-5
■ 第一章 基本介绍
量，进而降低风扇的转数以达到减少噪音的效果。 8. Windows Media Player 媒体播放器启动钮
当您按在窗口环境下按此钮时，系统即将启动窗口 Media Player 应用程序。
1-6
■ 第一章 基本介绍
■ 第一章 基本介绍
1. LCD 显示面板 计算机的数据及图形将显现这个屏幕上。
1-4
■ 第一章 基本介绍
2. 键盘 键盘可用来输入数据，并有内嵌的数码键盘及光标控 制键（请参考本章节后段）。
3. 触控板 触控板是一种内建的指针装置，其功能与鼠标类似。
4. LED 系统状态指示灯 LED 状态指示灯可显示某些按键功能的锁定/解锁状 态及硬盘/光驱的组件状态/无线网卡的启动与关闭。 请参阅章节后面相关的解说。 此 LED 亦显示系统的电源及电池充电的状态（请参 考本章节后段另有进一步说明）。
Copyright 2006 年 2 月 All Rights Reserved.
Microsoft 及 Windows 是 Microsoft Corporation 的注册商标。DOS、 Windows 95/98/ME/2000/NT/XP 是 Microsoft Corporation 的商标。 本手册中所引用之产品名称为其各自拥有者/公司之商标及/或注册商 标。 本手册中对于软件的介绍是在授权合约范围许可之下进行的。其软件仅 可在符合合约条件的情形下予以使用或复制。
1下列不属于ip地址的是-B）计算机及其外部设备
选择题1．一个完整的计算机系统包括____。
A)主机、键盘、显示器B)计算机及其外部设备C)系统软件与应用软件D)计算机的硬件系统和软件系统解答：一个完整的计算机系统是由硬件系统和软件系统组成的。
计算机的硬件是一个物质基础，而计算机软件是使硬件功能得以充分发挥的不可缺少的一部分。
因此，对于一个完整的计算机系统，这两者缺一不可。
本题的正确答案为D。
2．微型计算机的运算器、控制器及内存储器的总称是____。
A)CPU B)ALU C)MPU D)主机解答：CPU是中央处理器的简称，包括MPU和ALU；MPU是微处理器的简称；ALU是算术逻辑单元的简称；CPU和内存储器的总称为主机，它是微型机核心部分。
本题正确答案为D。
3．在微型计算机中，微处理器的主要功能是进行____。
A)算术逻辑运算及全机的控制B)逻辑运算C)算术逻辑运算D)算术运算解答：微处理器是计算机一切活动的核心，它的主要功能是实现算术逻辑运算及全机的控制。
本题正确答案为A。
4．反映计算机存储容量的基本单位是____。
A)二进制位B)字节C)字D)双字解答：存储容量大小是计算机的基本技术指标之一。
通常不是以二进制位、字或双字来表示，因为这些表示不规范，一般约定以字节作为反映存储容量大小的基本单位。
本题正确答案为B。
5．DRAM存储器的中文含义是____。
A)静态随机存储器B)动态只读存储器C)静态只读存储器D)动态随机存储器解答：动态随机存储器的原文是(Dynamic Random AccessMemory：DRAM)。
随机存储器有静态随机存储器和动态随机存储器之分。
半导体动态随机存储器DRAM的存储速度快，存储容量大，价格比静态随机存储器便宜。
通常所指的64MB或128MB内存，多为动态随机存储器DRAM。
本题正确答案为D。
6．微型计算机的发展是以____的发展为表征的。
A)微处理器B)软件C)主机D)控制器解答：微处理器是计算机一切活动的核心，因此微型计算机的发展是以微处理器的发展为表征的。
IPP详细入门及简单例程
IPP新手入门Intel IPP简介百度百科上是这样介绍的：IPP“Intel Integrated Performance Primitives” （ Intel IPP ）是一套跨平台的软件函数库，他提供了广泛的多媒体功能：音频解码器（例如： H263 、MPEG-4 ）、图像处理 (JPEG) 、信号处理、语音压缩（例如： G723 、 GSM 、 AMR ）和加密机制。
字面上的意思就是集成性能基元，IPP的Chief Architect李信弘（Shinn-Horng LEE）解释了Intel开发IPP的原因：开发IPP的目的是为了发挥CPU的性能。
销售IPP目的之一是了解哪些单位在用IPP，目的之二是用销售所得提供客户支持。
其次，IPP不光能对Intel的CPU进行提速，在非Intel的CPU上照样可以发挥提速功能。
但是当然IPP在Intel CPU 上发挥的能力要比AMD的CPU上强。
Intel IPP的安装与配置使用IPP的安装说明：按目标CPU型号，IPP库分为以下几种类型（参考ReleaseNotes.htm）：IA-32：32位处理器包括Intel® Core™2 Duo、Pentium® 4、Xeon®、Celeron®等，这是我们常用的CPU类型；Intel® 64：基于IA-32、带有64位扩展的CPU，操作系统为64位；Intel Itanium®：Intel Itanium® 2 处理器且操作系统为64位；Intel® IXP4XX Network Processors：包括某些用于嵌入式系统的CPU；本文档采用的安装包安装，安装的为w_ipp_ia32_p_6.1.2.041。
安装步骤如下：双击next选择安装路径，安装完毕即可安装完毕之后，运行ippiDemo.exe（或ippsDemo.exe从C：\ Program Files\Intel\ IPP\ 6.1.x.xxx \ia32 \Demo）。
第6章中央处理器(终)
第6章 中央处理器
本章学习内容
• 6.1中央处理器的功能和组成 • 6.2 控制器的组成和实现方法 • 6.3 时序系统与控制方式 • 6.4 微程序控制原理 • 6.5 控制单元的设计 • 6.6 流水线技术 • 6.7 精简指令系统计算机RISC
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第6章 中央处理器
本章学习要求
• 理解：CPU的功能和主要寄存器
内频=外频×倍频
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第6章 中央处理器
4.前端总线频率
前端总线通常用FSB表示，它是CPU和外界 交换数据的最主要通道，主要连接主存、显卡等 数据吞吐率高的部件，因此前端总线的数据传输 能力对计算机整体性能作用很大。
在Pentium 4出现之前，前端总线频率与外频 是相同的，因此往往直接称前端总线频率为外频。 随着计算机技术的发展，需要前端总线频率高于 外频，因此采用了QDR（Quad Date Rate）技术 或者其他类似的技术，使得前端总线频率成为外 频的2倍、4倍甚至更高。
CPU 的 字 长 是 指 在 单 位 时 间 内 同 时 处理的二进制数据的位数。CPU按照其处 理信息的字长可以分为：8位CPU、16位 CPU、32位CPU以及64位CPU等。
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第6章 中央处理器
2.内部工作频率
内部工作频率又称为内频或主频，它是衡
量CPU速度的重要参数。在其他性能指标相同 时，CPU的主频越高，CPU的速度也就越快。 内部时钟频率的倒数是时钟周期，这是CPU中
pro、Pentium Ⅱ/Ⅲ每个时钟周期可以执行3条
或更多的指令。
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第6章 中央处理器
3.外部工作频率
外部工作频率，也叫前端总线频率或系统 总线时钟频率，它是由主板为CPU提供的基准 时钟频率。由于正常情况下，CPU总线频率和 主存总线频率相同，所以也是CPU与主存交换 数据的频率。
看完你就明白的锁系列之自旋锁
看完你就明⽩的锁系列之⾃旋锁在上⼀篇⽂章中我们已经学习到了什么是悲观锁和乐观锁、悲观锁和乐观锁的实现、优缺点分别是什么。
其中乐观锁的实现之⼀ CAS 算法中提到了⼀个⾃旋锁的概念，为了全⾯理解 CAS 算法就⾸先需要了解⼀下⾃旋锁是什么，⾃旋锁的适⽤场景和优缺点分别是什么，别着急，下⾯为你⼀⼀列举。
⾃旋锁的提出背景由于在多处理器环境中某些资源的有限性，有时需要互斥访问(mutual exclusion)，这时候就需要引⼊锁的概念，只有获取了锁的线程才能够对资源进⾏访问，由于多线程的核⼼是CPU的时间分⽚，所以同⼀时刻只能有⼀个线程获取到锁。
那么就⾯临⼀个问题，那么没有获取到锁的线程应该怎么办？通常有两种处理⽅式：⼀种是没有获取到锁的线程就⼀直循环等待判断该资源是否已经释放锁，这种锁叫做⾃旋锁，它不⽤将线程阻塞起来(NON-BLOCKING)；还有⼀种处理⽅式就是把⾃⼰阻塞起来，等待重新调度请求，这种叫做互斥锁。
什么是⾃旋锁⾃旋锁的定义：当⼀个线程尝试去获取某⼀把锁的时候，如果这个锁此时已经被别⼈获取(占⽤)，那么此线程就⽆法获取到这把锁，该线程将会等待，间隔⼀段时间后会再次尝试获取。
这种采⽤循环加锁 -> 等待的机制被称为⾃旋锁(spinlock)。
⾃旋锁的原理⾃旋锁的原理⽐较简单，如果持有锁的线程能在短时间内释放锁资源，那么那些等待竞争锁的线程就不需要做内核态和⽤户态之间的切换进⼊阻塞状态，它们只需要等⼀等(⾃旋)，等到持有锁的线程释放锁之后即可获取，这样就避免了⽤户进程和内核切换的消耗。
因为⾃旋锁避免了操作系统进程调度和线程切换，所以⾃旋锁通常适⽤在时间⽐较短的情况下。
由于这个原因，操作系统的内核经常使⽤⾃旋锁。
但是，如果长时间上锁的话，⾃旋锁会⾮常耗费性能，它阻⽌了其他线程的运⾏和调度。
线程持有锁的时间越长，则持有该锁的线程将被OS(Operating System)调度程序中断的风险越⼤。