CPU 是否可以支持比英特尔指定的更多的 RAM？

Question 1

回答这个首要问题：“英特尔方舟通常是正确的，但并非总是正确的。”

任何产品说明书中的某些规格都可以视为“常见情况”，而外部因素可能会限制或提高性能。例如，Intel i7-8550U 将其基本时钟速度列为 1.80GHz。但是，可以通过使用支持硬件进行超频来超越此限制。

回答有关英特尔 i7-8550U 的具体问题，一些英特尔第 8 代 U 系列处理器可能原生支持 64GB 内存。[1]

摘自[1]第2.1.1.1节表2-5：

支持的 DDR4 非 ECC SODIMM 模块配置（H/U 处理器线）

原始卡版本	DIMM 容量	DRAM 设备技术	DRAM 组织	DRAM 设备数量	排名数	行/列地址位数	DRAM 内部存储体数量	页面大小
埃	32 GB	16 GB	2048M x 8	16	2	17/10	16	8K

通过使用两个这样的 32GB DIMM，可以实现 64GB 系统内存。

另外，为了在实践中看到这一点，以下是您所指的检测和利用 2x32GB 系统内存的确切硬件配置：

环境是您前面提到的运行 Debian Linux 的硬件设备之一

root@debian:~# dmidecode -qs system-product-name
FW6E

root@debian:~# uname -a
Linux debian 5.10.0-0.bpo.3-amd64 #1 SMP Debian 5.10.13-1~bpo10+1 (2021-02-11) x86_64 GNU/Linux

CPU是i7-8550U

root@debian:~# dmidecode -qs processor-version
Intel(R) Core(TM) i7-8550U CPU @ 1.80GHz

内存为 2x32GB DIMM

root@debian:~# dmidecode
Handle 0x0035, DMI type 16, 23 bytes
Physical Memory Array
        Location: System Board Or Motherboard
        Use: System Memory
        Error Correction Type: None
        Maximum Capacity: 64 GB
        Error Information Handle: Not Provided
        Number Of Devices: 4

Handle 0x0036, DMI type 17, 40 bytes
Memory Device
        Array Handle: 0x0035
        Error Information Handle: Not Provided
        Total Width: 64 bits
        Data Width: 64 bits
        Size: 32 GB
        Form Factor: SODIMM
        Set: None
        Locator: ChannelA-DIMM0
        Bank Locator: BANK 0
        Type: DDR4
        Type Detail: Synchronous Unbuffered (Unregistered)
        Speed: 2667 MT/s
        Manufacturer: Kingston
        Serial Number: C792668A
        Asset Tag: 9876543210
        Part Number: 9905744-067.A00G    
        Rank: 2
        Configured Memory Speed: 2400 MT/s
        Minimum Voltage: 1.2 V
        Maximum Voltage: 1.2 V
        Configured Voltage: 1.2 V

Handle 0x0037, DMI type 17, 40 bytes
Memory Device
        Array Handle: 0x0035
        Error Information Handle: Not Provided
        Total Width: Unknown
        Data Width: Unknown
        Size: No Module Installed
        Form Factor: Unknown
        Set: None
        Locator: ChannelA-DIMM1
        Bank Locator: BANK 1
        Type: Unknown
        Type Detail: None

Handle 0x0038, DMI type 17, 40 bytes
Memory Device
        Array Handle: 0x0035
        Error Information Handle: Not Provided
        Total Width: 64 bits
        Data Width: 64 bits
        Size: 32 GB
        Form Factor: SODIMM
        Set: None
        Locator: ChannelB-DIMM0
        Bank Locator: BANK 2
        Type: DDR4
        Type Detail: Synchronous Unbuffered (Unregistered)
        Speed: 2667 MT/s
        Manufacturer: Kingston
        Serial Number: C2A27761
        Asset Tag: 9876543210
        Part Number: 9905744-031.A00G    
        Rank: 2
        Configured Memory Speed: 2400 MT/s
        Minimum Voltage: 1.2 V
        Maximum Voltage: 1.2 V
        Configured Voltage: 1.2 V

Handle 0x0039, DMI type 17, 40 bytes
Memory Device
        Array Handle: 0x0035
        Error Information Handle: Not Provided
        Total Width: Unknown
        Data Width: Unknown
        Size: No Module Installed
        Form Factor: Unknown
        Set: None
        Locator: ChannelB-DIMM1
        Bank Locator: BANK 3
        Type: Unknown
        Type Detail: None

Handle 0x003A, DMI type 19, 31 bytes
Memory Array Mapped Address
        Starting Address: 0x00000000000
        Ending Address: 0x00FFFFFFFFF
        Range Size: 64 GB
        Physical Array Handle: 0x0035
        Partition Width: 2
[...]
Handle 0x003F, DMI type 20, 35 bytes
Memory Device Mapped Address
        Starting Address: 0x00000000000
        Ending Address: 0x007FFFFFFFF
        Range Size: 32 GB
        Physical Device Handle: 0x0036
        Memory Array Mapped Address Handle: 0x003A
        Partition Row Position: Unknown
        Interleave Position: 1
        Interleaved Data Depth: 2

Handle 0x0040, DMI type 20, 35 bytes
Memory Device Mapped Address
        Starting Address: 0x00800000000
        Ending Address: 0x00FFFFFFFFF
        Range Size: 32 GB
        Physical Device Handle: 0x0038
        Memory Array Mapped Address Handle: 0x003A
        Partition Row Position: Unknown
        Interleave Position: 2
        Interleaved Data Depth: 2
[...]

内存由操作系统分配

root@debian:~# free -h
              total        used        free      shared  buff/cache   available
Mem:           62Gi       156Mi        62Gi        24Mi       486Mi        61Gi

memtester 验证这不是一个错误，确保了 61Gi 的内存

root@debian:~# memtester 61Gi
memtester version 4.3.0 (64-bit)
Copyright (C) 2001-2012 Charles Cazabon.
Licensed under the GNU General Public License version 2 (only).

pagesize is 4096
pagesizemask is 0xfffffffffffff000
want 62464MB (65498251264 bytes)
got  62464MB (65498251264 bytes), trying mlock ...locked.
Loop 1:
  Stuck Address       : ok         
  Random Value        : ok
  Compare XOR         : ok
  Compare SUB         : ok
  Compare MUL         : ok
  Compare DIV         : ok
  Compare OR          : ok
  Compare AND         : ok
  Sequential Increment: ok
  Solid Bits          : ok         
  Block Sequential    : ok         
  Checkerboard        : ok         
  Bit Spread          : setting 109^C
(Process killed because this would take many hours to fully complete)

[1]：https://www.intel.com/content/www/us/en/products/docs/processors/core/8th-gen-core-family-datasheet-vol-1.html第八代和第九代英特尔® 酷睿™ 处理器家族和英特尔® 至强® E 处理器家族数据表，第 1 卷（共 2 卷）；修订版 008

免责声明：我在生产您在问题中提到的其中一台计算机的公司工作。

Answer