hardware profiling

RH442

Getting to know your hardware

Hardware profiling

Before tuning the performance, it‘s important to understand the capabilities of your system
    CPU 内部寄存器:硬件,时钟周期一致.1级缓存:静态内存,2级缓存:动态高速内存
    Memory 相对缓存更慢 
    Storage 更慢 到磁盘，终止。
Farthe from CPU,slower,bigger,less frequently accessed
Three elements of X86 machine, the ways to use system 针对X86结构
    I/O address
    IRQ
    DMA

CPU profile 指标

grep CPU /proc/cpuinfo

model name : Intel® Xeon® CPU E5-2620 v2 @ 2.10GHz

model name : Intel® Xeon® CPU E5-2620 v2 @ 2.10GHz

Model,Hz 操作系统认为你有两个cpu,Hz是跑步的频率，步子多大无关系
Caches size, L1, L2, L3, private or shared

lscpu

L1d cache:32k L1缓存分为数据缓存

L1i cache:32k &指令缓存

L2 cache:3072K

cpu(s):4 cpu数量为1

Thread(s) per core:1 每颗物理CPU，1为无超线程

Core(s) per socket:2 每颗物理CPU有两个核心

Socket(s):2 两颗物理CPU

CPU features-VT,Architecture 虚拟化,架构64/32

是否支持64 cat /proc/cpuinfo |egrep ‘(lm)|(pae)‘

Motherboard chipset 主板芯片组，决定主板和CPU效率

No.of sockets,cores,hyper thereading support

Interconnect between sockets 物理CPU多颗时。前端总线联系FSB/qpi/amd 物理CPU之间通讯手段

TOP CPUs

intel E7-8830
8 cores,16 threads 8核，16线程
24M cache, 2.13 GHz,QPI

AMD 6284 SE
16 cores
16M cache 2.7GHz

Memory profile 内存

Memory size, max allowed
> free -m

>cat /proc/meminfo

Memory technology,bandwidth and latency 内存第几代技术，以及带宽延时

>DDR2(2 bits),DDR3(4bits),DDR4(8 bits),Rambus(pS/2)

>Latency(wait time before read agin,in ns) 反映速度 纳秒级 列刷新频率

>ECC 内存故障修复 发现内存位失效 纠正 减速 slower safer

Method of memory accessing- UMA NUMA

    频率/2=速率 2133/2~~ 1G

UMA or SMP

>MCH 内存控制器 速度瓶颈  pcieX16 显卡占用 卡死了 这是北桥

>ICH 南桥连外设 sata usb pcie*1

NUMA 架构

>两个CPU自己管理自己内存，MCH内置到CPU

>IOH 伪北桥，IO控制器

>ICH 南桥一样

NUMA form apple Mac Pro

>MCH & ICH ->I/O HUB 内设& I/O CONTROLLER 外设..GPU很近

Storage Profile

Type of storage used
> Mechanical magnetic platters 盘片 ，磁碟

> SSD devices

Hardware RAID level, no. of disks, striping size

Interconnect type for direct attached storage 内部存储
>SATA SAS IDE    IDE没人用了 sata企业级,第三代sata完虐sas sas可靠

SCSI,FIBRE,CHANNEL,ISCSI PCI总线接驳，光纤，互联网

> 带宽，纳秒级，便宜

burstspped vs. average speed 顺序读写 随机读写

SSD

Electronic disk , no moving mechanical components

No start-up time

Very low latency on read and write

Faster than traditional HD sequence 500M/S 200M/S

Silent ,not so hot ,vibration free, magnet free,light,less power required

Much more expensive,lesser capacity

Potentially longer life time


MLC 一个单元存多位闪的多寿命短
SLC 很贵，非常贵

每次读至少一个block

####SSD TRIM COMMAND

when os erases a file, the file will typically be marked for deletion
SSD 不停做垃圾回收
ssd 挂载 fstab default,discard


>IDE UP 133MB/S

>SATA2 300

>SATA3 600

>SCSI 320

>USB2 60

>USB3 600

>ISCSI GIGA NIC 125

>FIBRE CHANNEL 531


###PCI EXPRESS

>1.0a 2Gb/s bandwidth:2.5GT/s singleLane:250Mb/s full16:8GB/s

>2.1 4      5       500     16

>3   8      8       1GB/s       32

Networking profile

Network card model
Network technology
Connection to switch(Speed)
Separated network, special purpose network -Storage,VDI,administration,useradta
I/O virtualization

>cmd

    >dmesg

    >/var/log/dmesg

    >lscpu,lscpu -p

    >getconf -a

    >x86info

profiling commands

>cmd

    >dmidecode

    >/sys/class/dmi

    >lspci [-v[-v[-v]]]

    >lsusb [-v]

    >ethtool

    >sosreport

    >powertop