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CPUID(1) General Commands Manual CPUID(1)

NAME

cpuid - Dump CPUID information for each CPU

SYNOPSIS

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 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); and 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.

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.
-f FILE, --file=FILE
Read raw hex information from FILE instead of from executions of the cpuid instruction.
-h, -H, --help
Display help information.
-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.)
-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.
-r, --raw
Display only raw hex information with no decoding.
-v, --version
Display cpuid version.

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

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
 
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
 
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
 
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
 
314554: Dual-Core Intel Xeon Processor 7100 Series Specification Update
 
314916: Dual-Core Intel Xeon Processor 3000 Series Specification Update
 
313515: Intel Pentium Dual-Core Processor Specification Update
 
316134: Quad-Core Intel Xeon Processor 3200 Series 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
 
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)
 
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
 
325122: Intel Xeon Processor E7-8800 / 4800 / 2800 Product Families Specification Update
 
325307: Intel Atom Processor Z600 Series Spefification Update
 
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
 
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
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:
 
20734: AMD Processor Recognition Application Note
 
21266: AMD-K6 Processor Revision Guide Model 6
 
21641: AMD-K6-2 Processor Revision Guide Model 8
 
21846: AMD-K6 Processor Revision Guide Model 7
 
22473: AMD-K6-III Processor Revision Guide Model 9
 
23614: AMD Athlon Processor Model 4 Revision Guide
 
23865: AMD Duron Processor Model 3 Revision Guide
 
24332: AMD Athlon Processor Model 6 Revision Guide
 
24806: AMD Duron Processor Model 7 Revision Guide
 
25481: CPUID Specification
 
25703: AMD Athlon Processor Model 8 Revision Guide
 
25759: Revision Guide for AMD Athlon 64 and AMD Opteron Processors
 
26094: BIOS and Kernel Developer's Guide for AMD Athlon 64 and AMD Opteron Processors
 
27532: AMD Athlon Processor Model 10 Revision Guide
 
31177H: AMD Geode NX Processors Data Book
 
31610: Revision Guide for AMD NPT Family 0Fh Processors
 
33234F: AMD Geode LX Processors Data Book
 
41322: Revision Guide for AMD Family 10h Processors
 
41788: Revision Guide for AMD Family 11h Processors
 
44739: Revision Guide for AMD Family 12h Processors
 
47534: Revision Guide for AMD Family 14h Models 00h-0Fh Processors
 
48063: Revision Guide for AMD Family 15h Models 00h-0Fh Processors
 
48931: Revision Guide for AMD Family 15h Models 10h-1Fh Processors
 
51810: Revision Guide for AMD Family 16h Models 00h-0Fh Processors
Information on the CPUID instruction and on specific CPUs is available from the following documents from Transmeta Corporation <http://www.transmeta.com/crusoe_docs/Crusoe_CPUID_5-7-02.pdf>:
 
Processor Recognition, 2002/05/07
Information on generic hypervisor CPUID levels is available from this proposal: <http://lwn.net/Articles/301888/>.
Information on KVM hypervisor CPUID levels is available from the Linux kernel under Documentation/kvm/cpuid.txt.
Information on Microsoft hypervisor CPUID levels is available from the following document from Microsoft: <http://msdn.microsoft.com/en-us/library/windows/hardware/ff542428%28v=vs.85%29.aspx>.
Also, information is available from the following web sites:
<http://www.sandpile.org/ia32/cpuid.htm>
 
<http://en.wikipedia.org/wiki/List_of_Intel_microprocessors>
 
<http://en.wikipedia.org/wiki/List_of_AMD_microprocessors>
 
<http://en.wikipedia.org/wiki/Category:X86_microprocessors>

AUTHOR

Todd Allen <cpuid@etallen.com>
23 Jan 2014 20140123