_ [Linux] Linuxでメモリ(DIMM)のSPDデータを参照する方法

試したのは RHEL/CentOS と openSUSE。UbuntuとかDebianでも似たようなもんだと思う。

1. eepromモジュールが組み込まれているか確認

   $ lsmod |grep ^eeprom
   eeprom                 40913  0

   もし組み込まれてなければmodprobeコマンドでロード

   $ modprobe eeprom

2. RHEL/CentOSの場合はlm_sensorsパッケージ、openSUSEの場合はi2c-toolsパッケージがインストールされてるか確認
   • RHEL/CentOS:

     $ rpm -qa |grep lm_sensors
     lm_sensors-2.10.7-9.el5

   • openSUSE:

     $ rpm -qa |grep i2c-tools
     i2c-tools-3.0.2-6.1.i586

   インストールされていなければパッケージをインストール
   
3. SPDデータを確認
   • RHEL/CentOS:

     $ decode-dimm.pl
     Memory Serial Presence Detect Decoder
     By Philip Edelbrock, Christian Zuckschwerdt, Burkart Lingner,
     Jean Delvare and others
     Version 2.10.6
     
     Decoding EEPROM: /sys/bus/i2c/drivers/eeprom/0-0050
     Guessing DIMM is in                             bank 1
     
     ---=== SPD EEPROM Information ===---
     EEPROM Checksum of bytes 0-62                   OK (0xC5)
     # of bytes written to SDRAM EEPROM              128
     Total number of bytes in EEPROM                 256
     Fundamental Memory type                         DDR2 SDRAM
     SPD Revision                                    1.2
     
     ---=== Memory Characteristics ===---
     Maximum module speed                            533MHz (PC2-4200)
     Size                                            1024 MB
     tCL-tRCD-tRP-tRAS                               5-4-4-11
     Supported CAS Latencies                         5, 4, 3
     Minimum Cycle Time (CAS 5)                      3.75 ns
     Maximum Access Time (CAS 5)                     0.5 ns
     Minimum Cycle Time (CAS 4)                      3.75 ns
     Maximum Access Time (CAS 4)                     0.5 ns
     Minimum Cycle Time (CAS 3)                      5 ns
     Maximum Access Time (CAS 3)                     0.6 ns
     
     ---=== Manufacturing Information ===---
     Manufacturer                                    Samsung
     Manufacturing Location Code                     0x01
     Part Number                                     M3 91T2953CZ3-CD5
     Revision Code                                   0x3343
     Manufacturing Date                              2006-W51
     Assembly Serial Number                          0x712B8840
     
     Decoding EEPROM: /sys/bus/i2c/drivers/eeprom/0-0052
     Guessing DIMM is in                             bank 3
     
     ---=== SPD EEPROM Information ===---
     EEPROM Checksum of bytes 0-62                   OK (0xC5)
     # of bytes written to SDRAM EEPROM              128
     Total number of bytes in EEPROM                 256
     Fundamental Memory type                         DDR2 SDRAM
     SPD Revision                                    1.2
     
     ---=== Memory Characteristics ===---
     Maximum module speed                            533MHz (PC2-4200)
     Size                                            1024 MB
     tCL-tRCD-tRP-tRAS                               5-4-4-11
     Supported CAS Latencies                         5, 4, 3
     Minimum Cycle Time (CAS 5)                      3.75 ns
     Maximum Access Time (CAS 5)                     0.5 ns
     Minimum Cycle Time (CAS 4)                      3.75 ns
     Maximum Access Time (CAS 4)                     0.5 ns
     Minimum Cycle Time (CAS 3)                      5 ns
     Maximum Access Time (CAS 3)                     0.6 ns
     
     ---=== Manufacturing Information ===---
     Manufacturer                                    Samsung
     Manufacturing Location Code                     0x01
     Part Number                                     M3 91T2953CZ3-CD5
     Revision Code                                   0x3343
     Manufacturing Date                              2006-W51
     Assembly Serial Number                          0x712B8824
     
     
     Number of SDRAM DIMMs detected and decoded: 2

   • openSUSE:

     $ decode-dimm