CPUID(1)

📦
this version · 9 versions
, in nixos 26.05, nixpkgs unstable, ubuntu stonking

This is the cpuid page from the General Commands Manual, aka CPUID(1) if you're being all formal 🎀 bestie, we're decoding CPU lore today.

🦋 NAME 🦋

cpuid — dump CPUID information for each CPU 💻✨

🎀 SYNOPSIS 🎀

The whole summoning ritual is literally just:

cpuid [options...]

🌸 DESCRIPTION 🌸

cpuid dumps detailed information about the CPU(s) gathered from the CPUID instruction, and also determines the exact model of CPU(s) from that information. It's giving hardware detective energy, no cap 🔍💅.

It dumps all information available from the CPUID instruction. The exact collection of information available varies between manufacturers and processors. The following information is available consistently on all modern CPUs:

  • vendor_id
  • version information (1/eax)
  • miscellaneous (1/ebx)
  • feature information (1/ecx)

It also produces synthetic fields based on information from multiple CPUID functions. Currently, the synthetic fields are:

  • the exact model of each CPU (but see LIMITATIONS below) as (synth)
  • the multiprocessing characteristics including the number of cores per chip (c) and the number of hyperthreads per core (t) as (multi-processing synth)
  • a decoding of the APIC physical ID as (APIC synth)

The determination of the model is based on the following information:

  • version information (1/eax), processor type
  • version information (1/eax), family
  • version information (1/eax), model
  • version information (1/eax), stepping id
  • version information (1/eax), extended family
  • version information (1/eax), extended model
  • feature information (1/ecx), virtual machine extensions
  • brand id (1/ebx)
  • brand (0x80000004)
  • cache and TLB information (2)
  • deterministic cache parameters (4/eax), extra processor cores
  • AMD extended brand id (0x80000001/ebx)
  • AMD extended processor signature (0x80000001/eax)
  • Transmeta processor revision ID (0x80860001/ebx & ecx)

The determination of the multiprocessing characteristics and decoding of APIC physical ID is based on the following information:

  • feature information (1/edx), hyper-threading / multi-core supported
  • miscellaneous (1/ebx), cpu count
  • deterministic cache parameters (4/eax), extra processor cores on this die
  • x2APIC features / processor topology (0xb)
  • AMD feature flags (0x80000001/ecx)
  • AMD Logical CPU cores (0x80000008/ecx), number of logical CPU cores - 1

In addition, a simpler and coarser determination of the CPU is performed using only the information listed above under version information (1/eax). It is provided as (simple synth) under version information (1/eax). However, it tends to be unable to distinguish between various modern CPUs. Sad but true 😭.

✨ OPTIONS ✨

cpuid accepts the following command line arguments:

  • -1, --one-cpu — Display information only for the first CPU. This cuts down on the output on a multiprocessor system, and is useful when certain that all CPUs are identical. One CPU, one vibe 💅.
  • -f FILE, --file=FILE — Read raw hex information from FILE instead of from executions of the cpuid instruction. If the filename is '-', instead read from standard input. File-based lore, iconic 🎀.
  • -l LEAF, --leaf=LEAF — Display information only for the specified LEAF. Leaf it to this option 🌿✨.
  • -s SUBLEAF, --subleaf=SUBLEAF — Display information only for the specified SUBLEAF. It requires the -l or --leaf option to specify the LEAF. Subleaf said what it said 💅.
  • -h, -H, --help — Display help information. Bestie rescue button 🫶.
  • -i, --inst — Use the CPUID instruction. The information it provides is reliable. It is not necessary to be root to use this option. (This option is the default.) Reliable and no root required? Slay 🔥.
  • -k, --kernel — Use the CPUID kernel module. The information does not seem to be reliable on all combinations of CPU type and kernel version. Typically, it is necessary to be root to use this option. Kernel mode: proceed with caution 💀.
  • -r, --raw — Display only raw hex information with no decoding. Just the raw tea, no garnish 🍓.
  • -v, --version — Display cpuid version. Version check, periodt 👑.

💀 LIMITATIONS 💀

There are numerous cases where there is no way to distinguish between various CPUs in the (synth) information. In some cases, the sizes of caches, number of cores, brand strings, etc., can be used to distinguish multiple CPUs with the same family and model. But there are cases where that information is insufficient. Whenever cpuid is unable to distinguish between multiple CPUs, it will list all known possibilities. It's not being vague on purpose, it's just that the CPUID tea is sometimes incomplete 😭.

If you believe that a certain processor should be distinguishable from another and it isn't, please inform the author of this tool. Feedback era, bestie 🫶.

The (multi-processing synth) information is unreliable on many processors. It faithfully reports the information provided by the CPUID instruction and decodes it as recommended by the processor manufacturers, but often that information is incorrect. The information seems to indicate the architecture's capabilities, rather than what the particular chip actually does. In particular, it seems commonplace to claim the presence of multiple hyperthreads when there is only one. So yes, it can be a little delulu 💀✨.

🌈 INFORMATION SOURCES 🌈

Information on the CPUID instruction and on specific CPUs is available from the following documents from Intel Corporation http://www.intel.com/support/processors/index.htm, with the specified Document Numbers:

  • 241618 — Intel Processor Identification and the CPUID Instruction, Application Note 485 ⭐ (lowkey the origin story of this whole page, iykyk)
  • 242480 — Pentium Processor Specification Update
  • 242689 — Pentium Pro Processor Specification Update
  • 243326 — 60- and 66-MHz Pentium Processor Specification Update
  • 243337 — Intel Pentium II Processor Specification Update
  • 243748 — Intel Celeron Processor Specification Update
  • 243776 — Intel Pentium II Xeon Processor Specification Update
  • 243887 — Mobile Intel Pentium II Processor Specification Update
  • 244444 — Mobile Intel Celeron Processor at 466 MHz, 433 MHz, 400 MHz, 366 MHz, 333 MHz, 300 MHz, and 266 MHz Specification Update
  • 244453 — Intel Pentium III Processor Specification Update
  • 244460 — Intel Pentium III Xeon Processor Specification Update
  • 245306 — Mobile Intel Pentium III Processor and Mobile Intel Pentium III Processor-M Specification Update
  • 245421 — Mobile Intel Celeron Processor (0.18u and 0.13u) Specification Update
  • 249199 — Intel Pentium 4 Processor Specification Update
  • 249678 — Intel Xeon Processor Specification Update
  • 250721 — Mobile Intel Pentium 4 Processor-M Specification Update
  • 251309 — Mobile Intel Celeron Processor on .13 Micron Process in Micro-FCPGA Package Specification Update
  • 252665 — Intel Pentium M Processor Specification Update
  • 253176 — Mobile Intel Pentium 4 Processor with 533 MHz System Bus Specification Update
  • 253666 — 64 and IA-32 Architectures Software Developer's Manual Volume 2A: Instruction Set Reference, A-M.
  • 276613 — Detecting Multi-Core Processor Topology in an IA-32 Platform by Khang Nguyen and Shihjong Kuo
  • 290741 — Intel Xeon Processor MP Specification Update
  • 290749 — Intel Celeron Processor in the 478-Pin Package Specification Update
  • 300303 — Intel Celeron M Processor Specification Update

okay real talk, bestie, this list is giving ✨infinity gauntlet of spec updates✨ — every chip family got its own little document and honestly? iconic commitment. keep scrolling, we're barely warmed up 💅

  • 302209 — Intel Pentium M Processor on 90nm Process with 2-MB L2 Cache Specification Update
  • 302352 — Intel Pentium 4 Processor on 90 nm Process Specification Update
  • 302354 — Intel Celeron D Processor 3xx Sequence Specification Update
  • 302402 — Intel Xeon Processor with 800 MHz System Bus
  • 302441 — Mobile Intel Pentium 4 Processor supporting Hyper-Threading Technology on 90-nm process technology Specification Update
  • 306752 — 64-bit Intel Xeon Processor MP with 1 MB L2 Cache Specification Update
  • 306757 — 64-bit Intel Xeon Processor MP with up to 8 MB L3 Cache Specification Update
  • 306832 — Intel Pentium Processor Extreme Edition and Intel Pentium D Processor Specification Update
  • 309159 — Dual-Core Intel Xeon Processor 2.80 GHz Specification Update
  • 309222 — Intel Core Duo Processor and Intel Core Solo Processor on 65 nm Process Specification Update
  • 309627 — Dual-Core Intel Xeon Processor 7000 Sequence Specification Update
  • 310307 — Intel Pentium D Processor 900 Sequence and Intel Pentium Processor Extreme Edition 955, 965 Specification Update
  • 310309 — Intel Pentium 4 Processor 6x1 Sequence Specification Update
  • 311392 — Dual-Core Intel Xeon Processor LV and ULV Specification Update
  • 311827 — Intel Celeron D Processor 300 Sequence Specification Update
  • 313065 — Dual-Core Intel Xeon Processor 5000 Series Specification Update
  • 313279 — Intel Core 2 Extreme Processor X6800 and Intel Core 2 Duo Desktop Processor E6000 Sequence Specification Update
  • 313356 — Dual-Core Intel Xeon Processor 5100 Series Specification Update
  • 313515 — Intel Pentium Dual-Core Processor Specification Update
  • 314079 — Intel Core 2 Duo and Intel Core 2 Solo Processor for Intel Centrino Duo Processor Technology Intel Celeron Processor 500 Series Specification Update
  • 314554 — Dual-Core Intel Xeon Processor 7100 Series Specification Update
  • 314916 — Dual-Core Intel Xeon Processor 3000 Series Specification Update
  • 315593 — Intel Core 2 Extreme Quad-Core Processor QX6000 Sequence and Intel Core 2 Quad Processor Q6000 Sequence Specification Update
  • 316134 — Quad-Core Intel Xeon Processor 3200 Series Specification Update
  • 316515 — Intel Pentium Dual-Core Processor Specification Update
  • 316964 — Intel Celeron Processor 400 Series Specification Update
  • 316982 — Intel Pentium Dual-Core Desktop Processor E2000 Series Specification Update
  • 317667 — Intel Celeron Processor 500 Series Specification Update
  • 318081 — Intel Xeon Processor 7200 and 7300 Series Specification Update
  • 318547 — Intel Celeron Processor 200 Sequence Specification Update
  • 318585 — Intel Xeon Processor 5400 Series Specification Update
  • 318586 — Intel Xeon Processor 5200 Series Specification Update
  • 318727 — Intel Core 2 Extreme Processor QX9000 Series and Intel Core 2 Quad Processor Q9000, Q9000S, Q8000, Q8000S Series Specification Update
  • 318733 — Intel Core 2 Duo Processor E8000 and E7000 Series Specification Update
  • 318915 — Intel Core 2 Duo Processor and Intel Core 2 Extreme Processor on 45-nm Process Specification Update
  • 318925 — Intel Celeron Dual-Core Processor E1000 Series Specification Update
  • 319006 — Dual-Core Intel Xeon Processor 3100 Series Specification Update
  • 319007 — Quad-Core Intel Xeon Processor 3300 Series Specification Update
  • 319129 — Intel Core 2 Extreme Processor QX9775 Specification Update
  • 319433 — Intel Architecture Instruction Set Extensions Programming Reference
  • 319536 — Intel Atom Processor Z5xx Series Specification Update
  • 319735 — Intel Celeron Dual-Core Processor T1x00 Series Specification Update
  • 319978 — Intel Atom Processor 200 Series Specification Update
  • 320047 — Intel Atom Processor N270 Series Specification Update

not the Atom netbook era making a comeback 😭 netbooks really said "we were there" — respect the lore fr fr 🫶

  • 320121 — Intel Core 2 Extreme Quad-Core Mobile Processor, Intel Core 2 Quad Mobile Processor, Intel Core 2 Extreme Mobile Processor, Intel Core 2 Duo Mobile Processor, Intel Core 2 Solo Mobile Processor and Intel Celeron Processor on 45-nm Process Specification Update
  • 320257 — Intel EP80579 Integrated Processor Product Line Specification Update
  • 320336 — Intel Xeon Processor 7400 Series Specification Update
  • 320468 — Intel Pentium Dual-Core E6000 and E5000 Series Specification Update
  • 320529 — Intel Atom Processor 300 Series Specification Update
  • 320767 — Intel Core i7-900 Mobile Processor Extreme Edition Series, Intel Core i7-800 and i7-700 Mobile Processor Series Specification Update
  • 320836 — Intel Core i7-900 Desktop Processor Extreme Edition Series and Intel Core i7-900 Desktop Processor Series Specification Update
  • 321324 — Intel Xeon Processor 5500 Series Specification Update
  • 321333 — Intel Xeon Processor 3500 Series Specification Update
  • 322166 — Intel Core i7-800 and i5-700 Desktop Processor Series Specification Update
  • 322373 — Intel Xeon Processor 3400 Series Specification Update
  • 322568 — Intel Celeron Processor E3x00 Series Specification Update
  • 322849 — Intel Atom Processor N400 Series Specification Update
  • 322861 — Intel Atom Processor D400 Series (Single Core) Specification Update
  • 322862 — Intel Atom Processor D500 Series (Dual Core) Specification Update
  • 322814 — Intel Core i7-600, i5-500, i5-400 and i3-300 Mobile Processor Series Specification Update
  • 322911 — Intel Core i5-600, i3-500 Desktop Processor Series and Intel Pentium Processor G6950 Specification Update
  • 323056 — Intel Xeon Processor L3406 Specification Update
  • 323179 — Intel Core i7-660UE, i7-620LE/UE, i7-610E, i5-520E, i3-330E and Intel Celeron Processor P4505, U3405 Series Datasheet Addendum Specification Update
  • 323105 — Intel Xeon Processor C5500/C3500 Series Specification Update
  • 323254 — Intel Core i7-900 Desktop Processor Extreme Edition Series and Intel Core i7-900 Desktop Processor Series on 32-nm Process Specification Update
  • 323338 — Intel Xeon Processor 3600 Series Specification Update
  • 323344 — Intel Xeon Processor 7500 Series Specification Update
  • 323372 — Intel Xeon Processor 5600 Series Specification Update
  • 323874 — Intel Pentium P6000 and U5000 Mobile Processor Series Specification Update
  • 324209 — Intel Atom Processor E6xx Series Specification Update
  • 324341 — Intel Atom Processor N500 Series Specification Update
  • Intel 64 Architecture Processor Topology Enumeration (Whitepaper) by Shih Kuo 🌸 (yes bestie, this one's a whitepaper, no doc number, we still cite it with respect)
  • 324456 — Intel Celeron Mobile Processor P4000 and U3000 Series Specification Update
  • 324643 — 2nd Generation Intel Core Processor Family Desktop Specification Update
  • 324827 — 2nd Generation Intel Core Processor Family Mobile Specification Update
  • 324972 — Intel Xeon Processor E3-1200 Product Family Specification Update
  • 325122 — Intel Xeon Processor E7-8800 / 4800 / 2800 Product Families Specification Update
  • 325307 — Intel Atom Processor Z600 Series Specification Update
  • 325309 — Intel Atom Processor Z6000 Series Specification Update
  • 325462 — Intel 64 and IA-32 Architectures Software Developer's Manual Combined Volumes: 1, 2A, 2B, 2C, 2D, 3A, 3B, 3C, 3D, and 4 📚 (the big one, the final boss of manuals, main character energy)
  • 325630 — Intel Atom Processor Z6xx Series Specification Update
  • 326140 — Intel Atom Processor N2000 and D2000 Series Specification Update
  • 326198 — Intel Core i7 Processor Family for the LGA-2011 Socket Specification Update
  • 326510 — Intel Xeon Processor E5 Family Specification Update
  • 326766 — Desktop 3rd Generation Intel Core Processor Family Specification Update
  • 326770 — Mobile 3rd Generation Intel Core Processor Family Specification Update
  • 326774 — Intel Xeon Processor E3-1200 v2 Product Family Specification Update
  • 327335 — Intel Xeon and Intel Core Processors For Communications Infrastructure Specification Update
  • 328105 — Intel Atom Processor Z2760 Specification Update
  • 328198 — Intel Atom Processor S1200 Product Family for Microserver Specification Update
  • 328205 — Intel Xeon Phi Coprocessor x100 Product Family Specification Update 🦋

and that's the end of the source list but NOT the end of the page, bestie — don't you dare close the tab, there's more coming 💜

…and the list just keeps going, bestie 🌈 — deeply obsessed with how many of these there are. Here's the rest of the Intel roster, no skips, no cap:

  • 328899 — Desktop 4th Generation Intel Core Processor Family Specification Update
  • 328903 — Mobile 4th Generation Intel Core Processor Family Specification Update
  • 328908 — Intel Xeon Processor E3-1200 v3 Product Family Specification Update
  • 329189 — Intel Xeon Processor E5 v2 Product Family Specification Update
  • 329376 — Intel Xeon E3-1125C v2, E3-1105C v2, Intel Core 3115C and Intel Pentium Processor B925C Specification Update
  • 329460 — Intel Atom Processor C2000 Product Family Specification Update
  • 329475 — Intel Atom Processor Z3600 and Z3700 Series Specification Update
  • 329597 — Intel Xeon Processor E7 v2 Product Family Specification Update
  • 329671/600827 — Intel Pentium Processor N3500-series, J2850, J2900 and Intel Celeron Processor N2900-series, N2800-series, J1800-series, J1900, J1750 Specification Update
  • 329676 — Intel Quark SoC X1000 Datasheet
  • 329901/600834 — Intel Atom Processor E3800 Specification Update
  • 330785 — Intel Xeon Processor E5 v3 Product Family Specification Update
  • 330836 — 5th Generation Intel Core Processor Family, Intel Core M Processor Family, Mobile Intel Pentium Processor Family, and Mobile Intel Celeron Processor Family Specification Update
  • 330841 — Intel Core i7 Processor Family for LGA2011-v3 Socket Specification Update
  • 332054 — Intel Xeon Processor D-1500 Product Family Specification Update
  • 332067 — Intel Atom Z8000 Processor Series Specification Update
  • 332095 — Intel N-Series Intel Pentium Processors and Intel Celeron Processors Specification Update
  • 332317 — Intel Xeon Processor E7 v3 Product Family Specification Update
  • 332381 — Mobile/Desktop 5th Generation Intel Core Processor Family Specification Update
  • 332689 — 6th Generation Intel Core Processor Family Specification Update
  • 333133 — Intel Xeon Processor E3-1200 v5 Product Family Specification Update
  • 333811 — Intel Xeon Processor E5-2600 v4 Product Family Specification Update
  • 334165 — Intel Xeon Processor E7-8800/4800 v4 Product Family Specification Update
  • 334208 — Intel Core i7 Processor Family for LGA2011-v3 Socket Specification Update
  • 334525 — Control-flow Enforcement Technology Preview
  • 334646 — Intel Xeon Phi Processor x200 Product Family Preliminary Specification Update
  • 334663 — 7th Generation Intel Processor Family Specification Update Supporting 7th Generation Intel Core Processor Families based on U/Y-Processor Line
  • 334820 — Intel Pentium and Celeron Processor N- and J- Series Specification Update
  • 335252 — 5-Level Paging and 5-Level EPT White Paper
  • 335718/730694 — Intel Xeon Processor E3-1200 v6 Product Family Specification Update
  • 335864 — Intel Celeron Processor J1800, J1900, N2807, and N2930 for Internet of Things Specification Update Addendum
  • 335901 — Intel Core X-Series Processor Family Specification Update
  • 336065/613537 — Intel Xeon Processor Scalable Family Specification Update
  • 336345 — Intel Atom Processor C3000 Product Family Specification Update
  • 336466 — 8th Generation Intel Processor Family for S-Processor Platforms Specification Update
  • 336505 — Intel Xeon Processor Scalable Family Specification Update
  • 336562 — Intel Pentium Silver and Intel Celeron Processors Specification Update
  • 337346 — 8th and 9th Generation Intel Core Processor Family Specification Update
  • 336907 — Intel Architecture Memory Encryption Technologies Specification
  • 338014 — Intel Xeon E-2100 and E-2200 Processor Family Specification Update
  • 338025 — 8th Generation Intel Core Processor Families Specification Update
  • 338848 — Second Generation Intel Xeon Scalable Processors Specification Update
  • 338854 — Intel Xeon D-2100 Processor Product Family Specification Update
  • 341079 — 10th Generation Intel Core Processor Families Specification Update
  • 343754 — Intel Trust Domain CPU Architectural Extensions
  • 344425 — Architecture Specification: Intel Trust Domain Extensions (Intel TDX) Module
  • 346466 — Intel Flexible Return and Event Delivery (FRED) Specification
  • 355828 — Intel Advanced Performance Extensions (Intel APX) Architecture Specification.
  • 615213 — 10th Generation Intel Core Processor Specification Update
  • 631123 — 11th Generation Intel Core Processor Family Specification Update
  • 634808 — 11th Generation Intel Core Processor Specification Update Supporting 11th Generation Intel Core Processor Families for S Platform, formerly known as Rocket Lake
  • 634542 — Intel Pentium Silver and Intel Celeron Processor Specification Update
  • 634897 — 3rd Generation Intel Xeon Scalable Processors, Codename Cooper Lake Specification Update
  • 636674 — Intel Atom x6000E Series, and Intel Pentium and Celeron N and J Series Processors for Internet of Things (IoT) Applications Specification Update - Public
  • 637780 — 3rd Gen Intel Xeon Scalable Processors, Codename Ice Lake Specification Update
  • 682436 — 12th Generation Intel Core Processor Specification Update Supporting 12th Generation Intel Core Processor for S Processor Line Platforms, formerly known as Alder Lake
  • 709192 — Intel Xeon E-2300 Processor Family Specification Update
  • 714069 — Intel Xeon D-1700 and D-1800 Processor Families Specification Update
  • 714071 — Intel Xeon D-2700 Processor Family Specification Update
  • 743844 — 13th Generation Intel Core Processors Datasheet, Volume 1 of 2 Supporting 13th Generation Intel Core Processor for S/P/PX/H/HX/U Processor Line Platforms, formerly known as Raptor Lake
  • 759603 — Intel Processor and Intel Core i3 N-Series Datasheet, Volume 1 of 2
  • 764616 — Intel Processor and Intel Core i3 N-series Specification Update
  • 772415 — 4th Gen Intel Xeon Scalable Processors Codename Sapphire Rapids Specification Update
  • 792254 — Intel Core Ultra Processor Specification Update
  • 793902 — 5th Gen Intel Xeon Processor Scalable Family, Codename Emerald Rapids Specification Update
  • 820922 — Intel Xeon 6700-Series Processor with E-Cores Specification Update
  • 827538 — Intel Core Ultra 200V Series Processors Specification Update
  • 834774 — Intel Core Ultra 200S Series Processors Specification Update
  • 835486 — Intel Xeon 6900/6700/6500-Series Processors with P-Cores Specification Update
  • 843306 — Intel Xeon 6700P-B/6500P-B-Series SoC with P-Cores Specification Update
  • 869992 — Intel Core Ultra Processors (Series 3) Specification Update
  • 871433 — Intel Core Series 2 Processor for Edge Platforms Datasheet
  • 872188 — Intel Core Ultra Processors (Series 3) Datasheet, Volume 1 of 2
  • 914196 — Intel Core Processors (Series 3) Specification Update

And then there's this lil cluster of docs that don't even get a number 😭 — they're just out here living their truth by title alone:

  • Intel Microcode Update Guidance
  • Branch History Injection and Intra-mode Branch Target Injection / CVE-2022-0001, CVE-2022-0002 / INTEL-SA-00598
  • Intel Transactional Synchronization Extensions (Intel TSX) Memory and Performance Monitoring Update for Intel Processors (Article ID 000059422)
  • Retpoline: A Branch Target Injection Mitigation
  • Special Register Buffer Data Sampling

okay so now we pivot to AMD 💅 — because yes, cpuid reads everybody's tea, not just Intel's:

Information on the CPUID instruction and on specific CPUs is available from the following documents from Advanced Micro Devices, Inc. <http://www.amd.com/us-en/Processors/TechnicalResources>, with the specified Publication Numbers:

(inhales) bestie the AMD list is coming up next and I'm not gonna lie to you, it's a whole vibe of its own 👑

…okay bestie, grab a snack, we are literally still scrolling the AMD document pile 😭 Not a single number skipped, promise — this is the exact list, in order, x and all:

  1. 20734: AMD Processor Recognition Application Note
  2. 21266: AMD-K6 Processor Revision Guide Model 6
  3. 21641: AMD-K6-2 Processor Revision Guide Model 8
  4. 21846: AMD-K6 Processor Revision Guide Model 7
  5. 22473: AMD-K6-III Processor Revision Guide Model 9
  6. 23614: AMD Athlon Processor Model 4 Revision Guide
  7. 23865: AMD Duron Processor Model 3 Revision Guide
  8. 24332: AMD Athlon Processor Model 6 Revision Guide
  9. 24594: AMD64 Architecture Programmer's Manual Volume 3: General-Purpose and System Instructions
  10. 24806: AMD Duron Processor Model 7 Revision Guide
  11. 25481: CPUID Specification
  12. 25703: AMD Athlon Processor Model 8 Revision Guide
  13. 25759: Revision Guide for AMD Athlon 64 and AMD Opteron Processors
  14. 26094: BIOS and Kernel Developer's Guide for AMD Athlon 64 and AMD Opteron Processors
  15. 27532: AMD Athlon Processor Model 10 Revision Guide
  16. 31177H: AMD Geode NX Processors Data Book
  17. 31610: Revision Guide for AMD NPT Family 0Fh Processors
  18. 33234F: AMD Geode LX Processors Data Book
  19. 40332: AMD64 Architecture Programmer's Manual: Volumes 1-5
  20. 41322: Revision Guide for AMD Family 10h Processors
  21. 41788: Revision Guide for AMD Family 11h Processors
  22. 44739: Revision Guide for AMD Family 12h Processors
  23. 47534: Revision Guide for AMD Family 14h Models 00h-0Fh Processors
  24. 48063: Revision Guide for AMD Family 15h Models 00h-0Fh Processors
  25. 48931: Revision Guide for AMD Family 15h Models 10h-1Fh Processors
  26. 51603: Revision Guide for AMD Family 15h Models 30h-3Fh Processors
  27. 51810: Revision Guide for AMD Family 16h Models 00h-0Fh Processors
  28. 53072: Revision Guide for AMD Family 16h Models 30h-3Fh Processors
  29. 54945: Processor Programming Reference (PPR) for AMD Family 17h Models 01h,0h, Revision B2 Processors
  30. 54945: Processor Programming Reference (PPR) for AMD Family 17h Models 01h,08h Revision B2 Processors
  31. 55370: Revision Guide for AMD Family 15h Models 70h-7Fh Processors
  32. 55449: Revision Guide for AMD Family 17h Models 00h-0Fh processors
  33. 55570-B1: Processor Programming Reference (PPR) for AMD Family 17h Model 18h, Revision B1 Processors
  34. 55766: Secure Encrypted Virtualization API Version 0.16 Technical Preview
  35. 55772-A1: Processor Programming Reference (PPR) for AMD Family 17h Model 20h, Revision A1 Processors
  36. 55898: Preliminary Processor Programming Reference (PPR) for AMD Family 19h Model 01h, Revision B1 Processors
  37. 56214: Processor Programming Reference (PPR) for AMD Family 19h Model 21h, Revision B0 Processors
  38. 56569: Processor Programming Reference (PPR) for AMD Family 19h Model 51h, Revision A1 Processors
  39. 55901: Preliminary Processor Programming Reference (PPR) for AMD Family 19h Model 11h, Revision B2 Processors
  40. 55922-A1: Processor Programming Reference (PPR) for AMD Family 17h Model 60h, Revision A1 Processors
  41. 55803: Preliminary Processor Programming Reference (PPR) for AMD Family 17h Model 31h, Revision B0 Processors
  42. 56176: Processor Programming Reference (PPR) for AMD Family 17h Model 71h, Revision B0 Processors
  43. 56375: AMD64 Technology Platform Quality of Service Extensions
  44. 57095: Revision Guide for AMD Family 19h Models 10h-1Fh Processors
  45. 57228: Processor Programming Reference (PPR) for AMD Family 19h Model A0h, Revision A2 Processors
  46. 57238: Processor Programming Reference (PPR) for AMD Family 1Ah Model 02h, Revision C1 Processors
  47. 57896: Processor Programming Reference (PPR) for AMD Family 1Ah Model 44h, Revision B0 Processors
  48. 58015: AMD EPYC 9004 Series Architecture Overview
  49. 58251: AMD Revision Guide for AMD Family 1Ah Models 00h-0Fh Processors
  50. 58268: AMD EPYC 8004 Series Architecture Overview
  51. 58730: AMD Revision Guide for AMD Family 1Ah Models 10h-1Fh Processors
  52. 69192: AMD64 Bit Matrix Multiply and Bit Reversal Instructions
  53. 69193: AMD64 Zen6 Platform Quality of Service (PQOS) Extensions
  54. 69201: AMD64 RMPOPT
  55. 69202: AMD64 Guest PMC Event Filtering
  56. 69203: AMD64 RMP Dirty
  57. 69204: AMD64 Enhanced SMT Protection
  58. 69205: AMD64 Zen6 Instruction Based Sampling (IBS) Extensions and Features
  59. 69206: AMD64 Collaborative Processor Performance Control (CPPC) Performance Priority
  60. 69208: AMD64 Page Modification Logging

And these next three are also part of that same AMD pile — no doc numbers on them, they're white papers:

  • AMD64 Technology Indirect Branch Control Extension (White Paper), Revision 4.10.18
  • AMD64 Technology Speculative Store Bypass Disable (White Paper), Revision 5.21.18
  • Technical Guidance For Mitigating Branch Type Confusion (White Paper), Revision 2022-07-12

Not-AMD sources, still iconic 🦋

Okay so the CPUID instruction and specific CPUs get documented by Transmeta Corporation too, in this one doc at http://www.transmeta.com/crusoe_docs/Crusoe_CPUID_5-7-02.pdf:

  • Processor Recognition, 2002/05/07

And Cyrix has receipts as well:

  • Application Note 112: Cyrix CPU Detection Guide
  • Cyrix 6x86 Processor, Instruction Set

The Linux kernel? Lowkey a whole study guide, fr. It's a source of info on CPUID flags via the X86_FEATURE_* definitions in arch/x86/include/asm/cpufeatures.h. And it can also teach you about Intel microarchitectures in arch/x86/include/asm/intel-family.h. Two files, zero excuses ✨

Generic hypervisor CPUID leaves? That's this proposal: http://lwn.net/Articles/301888/.

KVM hypervisor CPUID leaves? That's in the Linux kernel under Documentation/virtual/kvm/cpuid.txt.

XEN hypervisor CPUID leaves? Ngl those are deduced from source inspection — mainly xen's include/public/arch-x86/cpuid.h and arch/x86/traps.c. (Yes, "deduced". We read the source and vibed. 💅)

Microsoft hypervisor CPUID leaves? Thank these Microsoft docs: https://docs.microsoft.com/en-us/virtualization/hyper-v-on-windows/reference/tlfs and http://msdn.microsoft.com/en-us/library/windows/hardware/ff542428%28v=vs.85%29.aspx.

And there's more from these web sites:

👑 AUTHOR

The main character behind all of this: Todd Allen <cpuid@etallen.com> 🫶

And that's a wrap, bestie!! 🎀 This edition is from source date 20260503, dated 3 May 2026, and it's the CPUID(1) page — screenshot it, cite it, tattoo the version string on your arm, whatever slays 💖 Now go run cpuid and tell your CPU you read its whole lore. 🌈⭐

📦 where this page comes from