大多數情況下你可以從BIOS、產品目錄或者乾脆手動找出你的系統所持的最大記憶體。這裡，我們介紹一種簡單有用的技巧——使用dmidecode來找出系統支援的最大記憶體，這樣你就無需開啟機箱或者參照BIOS和產品目錄了。
什麼是 dmidecode?
就像你可能知道的一樣， dmidecode是一個將計算機DMI（又名SMBIOS）表的內容轉換為可讀格式的工具。這個表包含了系統硬體元件的介紹以及其他一些如序列號和IOS版本等有用的資訊。使用dmidecode你能夠獲取此項資訊，而無需去探測真實的硬體。
找出你的系統所支援的最大記憶體
請確定你已經在系統中安裝了dmidecode，我覺得你的作業系統應該已經自動安裝過了，不過並不非常確定。
在基於Deb的系統中安裝
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sudo apt-get install dmidecode |
在基於RPM的系統中安裝
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sudo yum install dmidecode |
在SUSE/openSUSE中安裝
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sudo zypper in dmidecode |
好了，我們已經安裝了dmidecode，接下來讓我們找出支援的最大記憶體。輸入以下命令：
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sudo dmidecode -t 16 |
輸出樣本
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# dmidecode 2.12 SMBIOS 2.6 present. Handle 0x0014, DMI type 16, 15 bytes Physical Memory Array Location: System Board Or Motherboard Use: System Memory Error Correction Type: None Maximum Capacity: 16 GB Error Information Handle: Not Provided Number Of Devices: 2 |
就像你看到的，我的系統支援最大記憶體到16G，並且有兩個記憶體插槽，簡單吧？
接下來，讓我們找出現在已經安裝的記憶體的詳細資訊。
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sudo dmidecode -t 17 |
輸出樣本
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# dmidecode 2.12 SMBIOS 2.6 present. Handle 0x0017, DMI type 17, 28 bytes Memory Device Array Handle: 0x0014 Error Information Handle: 0x0000 Total Width: Unknown Data Width: Unknown Size: No Module Installed Form Factor: DIMM Set: None Locator: DIMM_B Bank Locator: BANK 2 Type: Unknown Type Detail: None Speed: Unknown Manufacturer: Not Specified Serial Number: Not Specified Asset Tag: Not Specified Part Number: Not Specified Rank: Unknown Handle 0x0015, DMI type 17, 28 bytes Memory Device Array Handle: 0x0014 Error Information Handle: 0x0000 Total Width: 64 bits Data Width: 64 bits Size: 4096 MB Form Factor: SODIMM Set: None Locator: DIMM_A Bank Locator: BANK 0 Type: DDR3 Type Detail: Synchronous Speed: 1067 MHz Manufacturer: 014F Serial Number: 00092AF2 Asset Tag: 54114000 Part Number: JM1066KSN-4G Rank: Unknown |
就像上邊輸出的一樣，我在插槽1裡邊安裝了一個記憶體條。記憶體大小為4G，型別為DDR3，速度為1067 MHz。
同樣的，我們可以通過下邊命令得到完整的記憶體資訊。
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sudo dmidecode -t memory sudo dmidecode -t memory | less sudo dmidecode -t memory | more |
輸出樣本
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# dmidecode 2.12 SMBIOS 2.6 present. Handle 0x0014, DMI type 16, 15 bytes Physical Memory Array Location: System Board Or Motherboard Use: System Memory Error Correction Type: None Maximum Capacity: 16 GB Error Information Handle: Not Provided Number Of Devices: 2 Handle 0x0017, DMI type 17, 28 bytes Memory Device Array Handle: 0x0014 Error Information Handle: 0x0000 Total Width: Unknown Data Width: Unknown Size: No Module Installed Form Factor: DIMM Set: None Locator: DIMM_B Bank Locator: BANK 2 Type: Unknown Type Detail: None Speed: Unknown Manufacturer: Not Specified Serial Number: Not Specified Asset Tag: Not Specified Part Number: Not Specified Rank: Unknown Handle 0x0015, DMI type 17, 28 bytes Memory Device Array Handle: 0x0014 Error Information Handle: 0x0000 Total Width: 64 bits Data Width: 64 bits Size: 4096 MB Form Factor: SODIMM Set: None Locator: DIMM_A Bank Locator: BANK 0 Type: DDR3 Type Detail: Synchronous Speed: 1067 MHz Manufacturer: 014F Serial Number: 00092AF2 Asset Tag: 54114000 Part Number: JM1066KSN-4G Rank: Unknown |
如果你好奇想要知道整個系統的詳細資訊，例如主機板、記憶體、BIOS等，那麼可以輸入以下命令來獲取。
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sudo dmidecode |
輸出樣本
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 |
# dmidecode 2.12 SMBIOS 2.6 present. 48 structures occupying 2173 bytes. Table at 0x000EB840. Handle 0xDA00, DMI type 218, 251 bytes OEM-specific Type Header and Data: DA FB 00 DA B2 00 0D 5F 0F 37 40 7D 00 00 00 00 00 7E 00 01 00 00 00 DC 01 00 80 02 00 DD 01 00 80 03 00 75 01 01 80 01 00 76 01 02 80 01 00 2D 01 03 80 01 00 2E 01 03 80 00 00 81 01 07 80 00 00 82 01 07 80 01 00 83 01 08 80 00 00 84 01 08 80 01 00 85 01 06 80 00 00 86 01 06 80 01 00 58 02 05 80 00 00 57 02 05 80 01 00 9C 00 02 00 01 00 9B 00 02 00 00 00 8A 01 03 00 01 00 89 01 03 00 00 00 7F 01 04 00 00 00 80 01 04 00 01 00 53 01 05 00 00 00 52 01 05 00 01 00 7B 01 06 00 00 00 7C 01 06 00 01 00 94 01 07 00 00 00 93 01 07 00 01 00 7D 00 08 00 00 00 2D 00 09 00 01 00 2E 00 09 00 00 00 6E 00 0A 00 00 00 95 00 0B 00 01 00 96 00 0B 00 00 00 2F 02 0C 00 01 00 30 02 0C 00 00 00 50 02 0D 00 00 00 51 02 0D 00 01 00 52 02 0D 00 02 00 FF FF 00 00 00 00 Handle 0xDA01, DMI type 218, 59 bytes OEM-specific Type Header and Data: DA 3B 01 DA B2 00 0D 5F 0F 37 40 53 02 0D 00 03 00 54 02 0D 00 04 00 56 02 0D 00 05 00 4B 01 0E 00 01 00 4A 01 0E 00 00 00 EA 00 0F 00 01 00 EB 00 0F 00 00 00 FF FF 00 00 00 00 Handle 0x0004, DMI type 4, 42 bytes Processor Information Socket Designation: CPU 1 Type: Central Processor Family: Core i3 Manufacturer: Intel ID: A7 06 03 01 FF FB AB BE Signature: Type 0, Family 6, Model 42, Stepping 7 Flags: FPU (Floating-point unit on-chip) VME (Virtual mode extension) DE (Debugging extension) PSE (Page size extension) TSC (Time stamp counter) MSR (Model specific registers) PAE (Physical address extension) MCE (Machine check exception) CX8 (CMPXCHG8 instruction supported) APIC (On-chip APIC hardware supported) SEP (Fast system call) MTRR (Memory type range registers) PGE (Page global enable) MCA (Machine check architecture) CMOV (Conditional move instruction supported) PAT (Page attribute table) PSE-36 (36-bit page size extension) CLFSH (CLFLUSH instruction supported) DS (Debug store) ACPI (ACPI supported) MMX (MMX technology supported) FXSR (FXSAVE and FXSTOR instructions supported) SSE (Streaming SIMD extensions) SSE2 (Streaming SIMD extensions 2) SS (Self-snoop) HTT (Multi-threading) TM (Thermal monitor supported) PBE (Pending break enabled) Version: Intel(R) Core(TM) i3-2350M CPU @ 2.30GHz Voltage: 1.1 V External Clock: 100 MHz Max Speed: 2300 MHz Current Speed: 2300 MHz Status: Populated, Enabled Upgrade: Other L1 Cache Handle: 0x0005 L2 Cache Handle: 0x0006 L3 Cache Handle: 0x0007 Serial Number: To Be Filled By O.E.M. Asset Tag: To Be Filled By O.E.M. Part Number: To Be Filled By O.E.M. Core Count: 2 Core Enabled: 1 Thread Count: 2 Characteristics: 64-bit capable Handle 0x0005, DMI type 7, 19 bytes Cache Information Socket Designation: L1-Cache Configuration: Enabled, Not Socketed, Level 1 Operational Mode: Write Back Location: Internal Installed Size: 64 kB Maximum Size: 64 kB Supported SRAM Types: Other Installed SRAM Type: Other Speed: Unknown Error Correction Type: None System Type: Unified Associativity: 8-way Set-associative Handle 0x0006, DMI type 7, 19 bytes Cache Information Socket Designation: L2-Cache Configuration: Enabled, Not Socketed, Level 2 Operational Mode: Varies With Memory Address Location: Internal Installed Size: 512 kB Maximum Size: 512 kB Supported SRAM Types: Other Installed SRAM Type: Other Speed: Unknown Error Correction Type: None System Type: Unified Associativity: 8-way Set-associative Handle 0x0007, DMI type 7, 19 bytes Cache Information Socket Designation: L3-Cache Configuration: Enabled, Not Socketed, Level 3 Operational Mode: Varies With Memory Address Location: Internal Installed Size: 3072 kB Maximum Size: 3072 kB Supported SRAM Types: Other Installed SRAM Type: Other Speed: Unknown Error Correction Type: None System Type: Unified Associativity: Other Handle 0x0008, DMI type 8, 9 bytes Port Connector Information Internal Reference Designator: J1A1 Internal Connector Type: None External Reference Designator: PS2Mouse External Connector Type: PS/2 Port Type: Mouse Port Handle 0x0009, DMI type 8, 9 bytes Port Connector Information Internal Reference Designator: J1A1 Internal Connector Type: None External Reference Designator: Keyboard External Connector Type: PS/2 Port Type: Keyboard Port Handle 0x000A, DMI type 8, 9 bytes Port Connector Information Internal Reference Designator: J2A2B Internal Connector Type: None External Reference Designator: Video External Connector Type: DB-15 female Port Type: Video Port Handle 0x000B, DMI type 8, 9 bytes Port Connector Information Internal Reference Designator: J3A1 Internal Connector Type: None External Reference Designator: USB1 External Connector Type: Access Bus (USB) Port Type: USB Handle 0x000C, DMI type 8, 9 bytes Port Connector Information Internal Reference Designator: J3A1 Internal Connector Type: None External Reference Designator: USB2 External Connector Type: Access Bus (USB) Port Type: USB Handle 0x000D, DMI type 8, 9 bytes Port Connector Information Internal Reference Designator: J3A1 Internal Connector Type: None External Reference Designator: USB3 External Connector Type: Access Bus (USB) Port Type: USB Handle 0x000E, DMI type 8, 9 bytes Port Connector Information Internal Reference Designator: J5A1 Internal Connector Type: None External Reference Designator: LAN External Connector Type: RJ-45 Port Type: Network Port Handle 0x000F, DMI type 9, 17 bytes System Slot Information Designation: J6B2 Type: x16 PCI Express Current Usage: In Use Length: Long ID: 0 Characteristics: 3.3 V is provided Opening is shared PME signal is supported Bus Address: 0000:00:01.0 Handle 0x0010, DMI type 9, 17 bytes System Slot Information Designation: J6B1 Type: x1 PCI Express Current Usage: In Use Length: Short ID: 1 Characteristics: 3.3 V is provided Opening is shared PME signal is supported Bus Address: 0000:00:1c.3 Handle 0x0012, DMI type 11, 5 bytes OEM Strings String 1: Dell System String 2: 5[0003] String 3: 13[P18F] Handle 0x0013, DMI type 12, 5 bytes System Configuration Options Option 1: To Be Filled By O.E.M. Handle 0x001C, DMI type 21, 7 bytes Built-in Pointing Device Type: Touch Pad Interface: Bus Mouse Buttons: 2 Handle 0x001D, DMI type 22, 26 bytes Portable Battery Location: Sys. Battery Bay Manufacturer: Sanyo Serial Number: 5390 Name: DELL 4YRJH22 Chemistry: Lithium Ion Design Capacity: 45000 mWh Design Voltage: 10800 mV SBDS Version: 1.0 Maximum Error: 2% SBDS Manufacture Date: 2012-02-28 OEM-specific Information: 0x00000001 Handle 0x001E, DMI type 32, 20 bytes System Boot Information Status: No errors detected Handle 0x0020, DMI type 27, 12 bytes Cooling Device Type: Fan Status: OK OEM-specific Information: 0x00000000 Handle 0x0021, DMI type 28, 20 bytes Temperature Probe Description: CPU Internal Temperature Location: Processor Status: OK Maximum Value: 127.0 deg C Minimum Value: 0.0 deg C Resolution: 1.000 deg C Tolerance: 0.5 deg C Accuracy: Unknown OEM-specific Information: 0x00000000 Handle 0xB000, DMI type 176, 5 bytes OEM-specific Type Header and Data: B0 05 00 B0 00 Handle 0xB100, DMI type 177, 12 bytes OEM-specific Type Header and Data: B1 0C 00 B1 1A 0E 00 00 00 00 00 00 Handle 0x0025, DMI type 209, 12 bytes OEM-specific Type Header and Data: D1 0C 25 00 00 00 00 03 05 01 00 03 Handle 0x0026, DMI type 210, 12 bytes OEM-specific Type Header and Data: D2 0C 26 00 00 00 00 03 05 20 01 03 Handle 0x0027, DMI type 211, 13 bytes OEM-specific Type Header and Data: D3 0D 27 00 01 00 00 00 00 02 03 04 04 Strings: Front Handle 0x0028, DMI type 212, 57 bytes OEM-specific Type Header and Data: D4 39 28 00 70 00 71 00 01 49 50 48 9C 00 49 FC 01 9B 00 49 FC 00 7F 01 4A FB 04 80 01 4A FB 00 53 01 4A F7 08 52 01 4A F7 08 7B 01 4A EF 10 7C 01 4A EF 10 FF FF 00 00 00 Handle 0x002A, DMI type 217, 8 bytes OEM-specific Type Header and Data: D9 08 2A 00 01 02 00 00 Strings: Handle 0x002B, DMI type 219, 11 bytes OEM-specific Type Header and Data: DB 0B 2B 00 00 01 02 03 00 04 05 Strings: Handle 0x002C, DMI type 220, 22 bytes OEM-specific Type Header and Data: DC 16 2C 00 01 F0 00 00 02 F0 00 00 00 00 03 F0 04 F0 00 00 00 00 Handle 0x002D, DMI type 221, 19 bytes OEM-specific Type Header and Data: DD 13 2D 00 00 00 00 00 00 03 00 00 00 00 00 00 00 00 00 Handle 0x002E, DMI type 222, 16 bytes OEM-specific Type Header and Data: DE 10 2E 00 01 08 FF FF 00 00 00 00 00 00 00 00 Handle 0x0014, DMI type 16, 15 bytes Physical Memory Array Location: System Board Or Motherboard Use: System Memory Error Correction Type: None Maximum Capacity: 16 GB Error Information Handle: Not Provided Number Of Devices: 2 Handle 0x0016, DMI type 20, 19 bytes Memory Device Mapped Address Starting Address: 0x00000000000 Ending Address: 0x000FFFFFFFF Range Size: 4 GB Physical Device Handle: 0x0015 Memory Array Mapped Address Handle: 0x0018 Partition Row Position: 1 Interleave Position: 1 Interleaved Data Depth: 1 Handle 0x0017, DMI type 17, 28 bytes Memory Device Array Handle: 0x0014 Error Information Handle: 0x0000 Total Width: Unknown Data Width: Unknown Size: No Module Installed Form Factor: DIMM Set: None Locator: DIMM_B Bank Locator: BANK 2 Type: Unknown Type Detail: None Speed: Unknown Manufacturer: Not Specified Serial Number: Not Specified Asset Tag: Not Specified Part Number: Not Specified Rank: Unknown Handle 0x0018, DMI type 19, 15 bytes Memory Array Mapped Address Starting Address: 0x00000000000 Ending Address: 0x000FFFFFFFF Range Size: 4 GB Physical Array Handle: 0x0014 Partition Width: 2 Handle 0x002F, DMI type 13, 22 bytes BIOS Language Information Language Description Format: Abbreviated Installable Languages: 1 eng Currently Installed Language: eng Handle 0x0030, DMI type 131, 64 bytes OEM-specific Type Header and Data: 83 40 30 00 31 00 00 00 00 00 00 00 00 00 00 00 F8 00 4B 1C FF FF FF FF 01 00 00 00 00 00 07 00 AD 04 04 00 00 00 00 00 C8 00 FF FF 00 00 00 00 00 00 00 00 32 00 00 00 76 50 72 6F 00 00 00 00 Handle 0x0029, DMI type 216, 9 bytes OEM-specific Type Header and Data: D8 09 29 00 01 02 01 00 00 Strings: INTEL 0000 Handle 0x0000, DMI type 0, 24 bytes BIOS Information Vendor: Dell Inc. Version: A05 Release Date: 08/03/2012 Address: 0xF0000 Runtime Size: 64 kB ROM Size: 2048 kB Characteristics: MCA is supported PCI is supported BIOS is upgradeable BIOS shadowing is allowed ESCD support is available Boot from CD is supported Selectable boot is supported BIOS ROM is socketed EDD is supported 5.25"/1.2 MB floppy services are supported (int 13h) 3.5"/720 kB floppy services are supported (int 13h) 3.5"/2.88 MB floppy services are supported (int 13h) Print screen service is supported (int 5h) 8042 keyboard services are supported (int 9h) Serial services are supported (int 14h) Printer services are supported (int 17h) CGA/mono video services are supported (int 10h) ACPI is supported USB legacy is supported ATAPI Zip drive boot is supported BIOS boot specification is supported Targeted content distribution is supported BIOS Revision: 0.5 Firmware Revision: 0.5 Handle 0x0002, DMI type 2, 15 bytes Base Board Information Manufacturer: Dell Inc. Product Name: 01HXXJ Version: A05 Serial Number: .JSQ7PA1.CN7117623M00J2. Asset Tag: Not Specified Features: Board is a hosting board Board is replaceable Location In Chassis: To Be Filled By O.E.M. Chassis Handle: 0x0003 Type: Motherboard Contained Object Handles: 0 Handle 0x0003, DMI type 3, 21 bytes Chassis Information Manufacturer: Dell Inc. Type: Portable Lock: Not Present Version: Not Specified Serial Number: JSR1 Asset Tag: Not Specified Boot-up State: Safe Power Supply State: Safe Thermal State: Safe Security Status: None OEM Information: 0x00000000 Height: Unspecified Number Of Power Cords: 1 Contained Elements: 0 Handle 0x0001, DMI type 1, 27 bytes System Information Manufacturer: Dell Inc. Product Name: Inspiron N5050 Version: Not Specified Serial Number: JSR1 UUID: 4C4C4544-0053-5110-8029-CAC05241 Wake-up Type: Power Switch SKU Number: To be filled by O.E.M. Family: Handle 0x0024, DMI type 208, 12 bytes OEM-specific Type Header and Data: D0 0C 24 00 02 05 FE 00 04 05 01 02 Strings: 20120323 20120323 Handle 0x0011, DMI type 10, 6 bytes On Board Device Information Type: Video Status: Enabled Description: Mobile Intel SandyBridge HD Graphics Handle 0x0015, DMI type 17, 28 bytes Memory Device Array Handle: 0x0014 Error Information Handle: 0x0000 Total Width: 64 bits Data Width: 64 bits Size: 4096 MB Form Factor: SODIMM Set: None Locator: DIMM_A Bank Locator: BANK 0 Type: DDR3 Type Detail: Synchronous Speed: 1067 MHz Manufacturer: 014F Serial Number: 0009F2 Asset Tag: 54114000 Part Number: JM1066-4G Rank: Unknown Handle 0x0031, DMI type 127, 4 bytes End Of Table |
好了，就是這樣。