x86
Instruction Set Architecture

General

• History
• Families

Variants

• x86-16
• x86-32
• x86-64

Topics

• Instructions
• Addressing Modes
• Calling Convention
• Microarchitectures
• Model-Specific Register
• CPUID
• Assembly
• Interrupts
• Registers
• Micro-Ops
• Timer

CPUIDs

• AMD's CPUIDs
• Intel's CPUIDs

Modes

• Real
• Long
• Protected

Extensions(all)

• 3DNow!
• E3DNow!
• ABM
• ADX
• AES
• AMX
• AVX
• AVX2
• AVX-512
• BMI1
• BMI2
• CLMUL
• F16C
• FMA3
• FMA4
• FPU
• MMX
• EMMX
• MPX
• PMEM
• PREFETCH
• RdRAND
• SEV
• SGX
• SHA
• SME
• TSME
• SMM
• SMX
• SSE
• SSE2
• SSE3
• SSE4.1
• SSE4.2
• SSE4a
• SSE5
• SSSE3
• TBM
• TSX
• TME
• MKTME
• XOP

Below is a list of Intel's CPUID broken down by their respective core names and microarchitecture:

CPUIDs

Family 19

Microarchitecture	Core	Platform	Extended Family	Family	Extended Model	Model	Family • Model
Diamond Rapids (2025)	Panther Cove X (P) • 18A DMR-AP/SP (LGA9324)	Mountain Stream	0x4	0xF	0x0	0x1	Family 19 Model 1
Nova Lake (2026)	Coyote Cove (P) • 18A Arctic Wolf (E) • NVL-S/H		0x4	0xF	0x0	0x0	Family 19 Model 0

Key changes from Granite Rapids:

• Core: Redwood Cove+ → Panther Cove X (P-core), Platform: Eagle Stream → Mountain Stream

Family 15

• Intel • Core • Xeon

Microarchitecture	Core	Fab node	Extended Family	Family	Extended Model	Model	Family • Model
Modified Pentium M (2006)	Cedar Mill (2C) (Xeon Dempsey)	65 nm	0	0xF	0x0	0x6	Family 15 Model 6
Netburst (P68) (2000)	Prescott (2M)	90 nm	0	0xF	0x0	0x4	Family 15 Model 4
	Prescott	90 nm	0	0xF	0x0	0x3	Family 15 Model 3
	Northwood	130 nm	0	0xF	0x0	0x2	Family 15 Model 2
	Willamette (Xeon Foster)	180 nm	0	0xF	0x0	0x1	Family 15 Model 1

Family 11

Microarchitecture	Core	Extended Family	Family	Extended Model	Model	Family • Model
Knights Corner (2011)	62 cores (22 nm)	0	0xB	0x0	0x1	Family 11 Model 1
Knights Ferry (2010)	32 cores (45 nm)	0	0xB	0x0	0x0	Family 11 Model 0

Family 6

MIC Architecture

• Xeon Phi •

Microarchitecture	Core	Extended Family	Family	Extended Model	Model	Family • Model
Knights Mill Knights Hill, Knights Peak	Xeon Phi 64C/256T 14 nm	0	0x6	0x8	0x5	Family 6 Model 133
Knights Landing	Xeon Phi 72C/288T 14 nm	0	0x6	0x5	0x7	Family 6 Model 87

Small Cores

Intel's client small cores refers to Intel low-power SoCs that ship in low power

laptops, tablets, embedded devices, and low-power servers.

• "Small Cores" Processors (Atom/E-Core) •

Microarchitecture	Core	Extended Family	Family	Extended Model	Model	Family • Model
Darkmont (2025)	Clearwater Forest CWF-AP/CWF-SP Wildcat Lake WCL Panther Lake U/H/P	0	0x6	. 0xD 0x? 0xC	. 0xD 0x? 0xC	Darkmont_X IFM (6, 0xDD) . .
Skymont (2024)	Arrow Lake S/U Lunar Lake MX/V	0	0x6	0xB 0xB	0x5 0xC	0xB 0x5, 0xC 0x5/0x6 0xB 0xC/0xD
Crestmont (2023)	Sierra Forest SP Meteor Lake S/N Grand Ridge	0	0x6	0xA 0xA 0xB	0xF 0xA 0x6	IFM (6, 0xAF) 0xA, 0xB, 0xC IFM (6, 0xB6)
Gracemont (2021)	Alder Lake N Raptor Lake S/N Twin Lake S	0	0x6	0xB 0xB 0x?	0xE 0x7 0x?	IFM (6, 0xBE) 0xB 0x7/0xB 0xE ?
Tremont (2020)	Jasper Lake (L)	0	0x6	0x9	0xC	Family 6 Model 156
	Elkhart Lake	0	0x6	0x9	0x6	Family 6 Model 150
	Jacobsville (D)	0	0x6	0x8	0x6	IFM (6, 0x86)
	Lakefield	0	0x6	0x8	0xA	Family 6 Model 138
Goldmont Plus	Gemini Lake	0	0x6	0x7	0xA	Family 6 Model 122
Goldmont	Denverton (D)	0	0x6	0x5	0xF	Family 6 Model 95
	Apollo Lake, Broxton, Willow Trail	0	0x6	0x5	0xC	Family 6 Model 92
Airmont	Cherry Trail, Braswell	0	0x6	0x4	0xC	Family 6 Model 76
	Lightning Mountain (NP)	0	0x6	0x7	0x5	IFM (6, 0x75)
Silvermont	SoFIA	0	0x6	0x5	0xD	Family 6 Model 93
	Anniedale (MID2)	0	0x6	0x5	0xA	Family 6 Model 90
	Avoton, Rangeley (D)	0	0x6	0x4	0xD	Family 6 Model 77
	Merriefield, Tangier (MID)	0	0x6	0x4	0xA	Family 6 Model 74
	Bay Trail, Valleyview	0	0x6	0x3	0x7	Family 6 Model 55
Saltwell	Cedarview	0	0x6	0x3	0x6	Family 6 Model 54
	Cloverview (TAB)	0	0x6	0x3	0x5	Family 6 Model 53
	Penwell (MID)	0	0x6	0x2	0x7	Family 6 Model 39
Bonnell	Silverthorne, Lincroft (MID)	0	0x6	0x2	0x6	Family 6 Model 38
	Diamondville, Pineview	0	0x6	0x1	0xC	Family 6 Model 28

Big Cores (Server)

Intel's server big cores refers to Intel workstation and data center SoCs that ship

in most enterprise desktops, workstations, and servers.

Microarchitecture	Core	Extended Family	Family	Extended Model	Model	Family • Model
Clearwater Forest (2025)	CWF-AP (LGA7529) Darkmont (E) • 18A CWF-SP (LGA4710)	0	0x6	0xD	0xD	Family 6 Model 221
Sierra Forest (2024)	Crestmont (E) SP SRF-SP	0	0x6	0xA	0xF	Family 6 Model 175
Granite Rapids (2024)	Redwood Cove (D)	0	0x6	0xA	0xE	Family 6 Model 174
	Redwood Cove	0	0x6	0xA	0xD	Family 6 Model 173
Emerald Rapids (2023)	Golden Cove	0	0x6	0xC	0xF	Family 6 Model 207
Sapphire Rapids (2023)	Golden Cove SP	0	0x6	0x8	0xF	Family 6 Model 143
Ice Lake (Server)	DE	0	0x6	0x6	0xC	Family 6 Model 108
	SP	0	0x6	0x6	0xA	Family 6 Model 106
Cooper Lake (stepping 11)	?	0	0x6	0x5	0x5	Family 6 Model 85
Cascade Lake (stepping 5-7)	SP, X, W
Skylake (Server)	SP, X, DE, W
Broadwell (Server)	DE, Hewitt Lake	0	0x6	0x5	0x6	Family 6 Model 86
	E, EP, EX	0	0x6	0x4	0xF	Family 6 Model 79
Haswell (Server)	E, EP, EX	0	0x6	0x3	0xF	Family 6 Model 63
Ivy Bridge (Server)	E, EN, EP, EX	0	0x6	0x3	0xE	Family 6 Model 62
Sandy Bridge (Server)	E, EN, EP	0	0x6	0x2	0xD	Family 6 Model 45
Westmere (Server)	EX	0	0x6	0x2	0xF	Family 6 Model 47
	EP, Gulftown	0	0x6	0x2	0xC	Family 6 Model 44
Nehalem (Server)	EX	0	0x6	0x2	0xE	Family 6 Model 46
	Lynnfield	0	0x6	0x1	0xE	Family 6 Model 30
	EP, WS, Bloomfield	0	0x6	0x1	0xA	Family 6 Model 26
Penryn (Server)	Dunnington	0	0x6	0x1	0xD	Family 6 Model 29
	Harpertown, Penryn QC, Wolfdale, Yorkfield	0	0x6	0x1	0x7	Family 6 Model 23
P6 (Pentium)		0	0x6	0x0	0xA	Family 6 Model 10

Big Cores (Client)

Intel's client big cores refers to Intel mainstream SoCs that ship in most tablets, laptops, and desktop devices.

Microarchitecture	Core	Extended Family	Family	Extended Model	Model	Family • Model
• "Hybrid" Processors (P-Core/E-Core) • Intel Core • Intel Atom
Razer Lake (2027)	Griffin Cove (P) Golden Eagle (E) • RZL-M/H	0	0x6	0xC	0x?	?
Nova Lake (2026)	Coyote Cove (P) Arctic Wolf (E) • NVL-S/H	0	0x6	0xC	0x?	?
Wildcat Lake (2025)	Cougar Cove (P) Darkmont (LPE) • WCL, 2P+4LPE	0	0x6	0xC	0xD ?	?
Panther Lake (2025)	Cougar Cove (P) Darkmont (E) • PTL-U/H/P	0	0x6	0xC	0xC	Family 6 Model 204
Bartlett Lake (2025) (Raptor Lake Refresh)	Raptor Cove (P) • U • H Gracemont (E) • BLL-N	0	0x6	0xB	0xF 0xE	Family 6 Model 191 ? Family 6 Model 190 ?
	Raptor Cove (P) • BLL-P	0	0x6	0xB	0xA	Family 6 Model 186
	Raptor Cove (P) • BLL-S Enhanced Gracemont (E)	0	0x6	0xB	0x7	Family 6 Model 183
Lunar Lake (2024)	• LNL-V • LNL-MX Lion Cove (P) Skymont (E/LPE)	0	0x6	0xB	0xD 0xC	Family 6 Model 189 ? BD Family 6 Model 188 ? BC
Arrow Lake (2024)	• ARL-S	0	0x6	0xC	0x6	Family 6 Model 198 ? C6
	Lion Cove (P) • ARL-H Skymont (E/LPE)	0	0x6	0xC	0x5	Family 6 Model 197 ? C5
	• ARL-U	0	0x6	0xB	0x5	Family 6 Model 181 ? B5
Meteor Lake (2023)	Redwood Cove (P) Crestmont (E) • MTL-S	0	0x6	0xA	0xC	Family 6 Model 172 ? AC
	• MTL-N Crestmont (E)	0	0x6	0xA	0xB 0xA	Family 6 Model 171 ? AB Family 6 Model 170 ? AA
Raptor Lake (2022)	Raptor Cove (P) • U • H Gracemont (E) • RPL-N	0	0x6	0xB	0xF 0xE	Family 6 Model 191 ? Family 6 Model 190 ?
	Raptor Cove (P) • RPL-P	0	0x6	0xB	0xA	Family 6 Model 186
	Raptor Cove (P) • RPL-S Enhanced Gracemont (E)	0	0x6	0xB	0x7	Family 6 Model 183
Alder Lake (2021)	Golden Cove (P) • ADL-P	0	0x6	0x9	0xA	Family 6 Model 154
	Alder Lake S • ADL-S Gracemont (E)	0	0x6	0x9	0x7	Family 6 Model 151
• "Mono" Processors (P-Core) •
Rocket Lake (2021)	Cypress Cove (P) • RKL-S, RKL-U	0	0x6	0xA	0x7	Family 6 Model 167
Comet Lake (2020)	• CML-U	0	0x6	0xA	0x6	Family 6 Model 166 ?
	• CML-H • CML-S	0	0x6	0xA	0x5	Family 6 Model 165
Tiger Lake	• TGL-H (H35)	0	0x6	0x8	0xD	Family 6 Model 141
	Willow Cove • TGL-U (UP)	0	0x6	0x8	0xC	Family 6 Model 140
Ice Lake (Client)	Sunny Cove • ICL-U	0	0x6	0x7	0xE	Family 6 Model 126
	• ICL-Y	0	0x6	0x7	0xD	Family 6 Model 125 ?
Cannon Lake	Palm Cove • CNL-U (Y)	0	0x6	0x6	0x6	Family 6 Model 102
Coffee Lake	• CFL-H • CFL-S • CFL-E	0	0x6	0x9	0xE	Family 6 Model 158
	• CFL-U (R) (Stepping 10)	0	0x6	0x8	0xE	Family 6 Model 142
Kaby Lake	• KBL-DT • KBL-X • KBL-H • KBL-S (G)	0	0x6	0x9	0xE	Family 6 Model 158
	• KBL-Y • KBL-U (R)	0	0x6	0x8	0xE	Family 6 Model 142
Amber Lake	• AML-Y (Stepping 9)	0	0x6	0x8	0xE	Family 6 Model 142
Whiskey Lake	• WHL-U (Stepping 11/12)
Skylake (Client)	• SKL-H • SKL-S • SKL-DT	0	0x6	0x5	0xE	Family 6 Model 94
	• SKL-Y • SKL-U	0	0x6	0x4	0xE	Family 6 Model 78
Broadwell (Client)	• BDW-H • BDW-C • BDW-W	0	0x6	0x4	0x7	Family 6 Model 71
	• BDW-Y • BDW-U • BDW-S	0	0x6	0x3	0xD	Family 6 Model 61
Haswell (Client)	• HSW-MB (GT3E)	0	0x6	0x4	0x6	Family 6 Model 70
	• HSW-U (ULT/ULX/Y)	0	0x6	0x4	0x5	Family 6 Model 69
	• HSW-S (H/DT)	0	0x6	0x3	0xC	Family 6 Model 60
Ivy Bridge (Client)	• IVB-M • IVB-H (Gladden)	0	0x6	0x3	0xA	Family 6 Model 58
Sandy Bridge (Client)	• SNB-M • SNB-H (Celeron)	0	0x6	0x2	0xA	Family 6 Model 42
Westmere (Client)	Arrandale, Clarkdale	0	0x6	0x2	0x5	Family 6 Model 37
Nehalem (Client)	Auburndale, Havendale	0	0x6	0x1	0xF	Family 6 Model 31
	Clarksfield	0	0x6	0x1	0xE	Family 6 Model 30
Penryn (Client)	Penryn, Wolfdale, Yorkfield	0	0x6	0x1	0x7	Family 6 Model 23
Core (Client)	Merom L	0	0x6	0x1	0x6	Family 6 Model 22
	Merom	0	0x6	0x0	0xF	Family 6 Model 15
Modified Pentium M	Yonah	0	0x6	0x0	0xE	Family 6 Model 14
Pentium M	Tolapai	0	0x6	0x1	0x5	Family 6 Model 21
	Dothan	0	0x6	0x0	0xD	Family 6 Model 13
	Banias	0	0x6	0x0	0x9	Family 6 Model 9
P6 (Pentium)	Tualatin (Pentium III)	0	0x6	0x0	0xB	Family 6 Model 11
	Coppermine, Coppermine T	0	0x6	0x0	0x8	Family 6 Model 8
	Katmai	0	0x6	0x0	0x7	Family 6 Model 7
		0	0x6	0x0	0x6	Family 6 Model 6
	Deschutes (Pentium III)	0	0x6	0x0	0x5	Family 6 Model 5
	Klamath (Pentium II)	0	0x6	0x0	0x3	Family 6 Model 3
	Pentium Pro	0	0x6	0x0	0x1	Family 6 Model 1

Family 5

Microarchitecture	Core	Extended Family	Family	Extended Model	Model	Family • Model
Lakemont (Lake)	Quark D1000	0	0x5	0x0	0xA	Family 5 Model 10
	Quark X1000	0	0x5	0x0	0x9	Family 5 Model 9
P5 (1993) • Pentium	P55C (Mobile)	0	0x5	0x0	0x8	Family 5 Model 8
		0	0x5	0x0	0x7	Family 5 Model 7
	P55C (Pentium MMX)	0	0x5	0x0	0x4	Family 5 Model 4
	P54CS (Pentium 75)	0	0x5	0x0	0x2	Family 5 Model 2
	P54, P54CQS	0	0x5	0x0	0x1	Family 5 Model 1
	P5 (A-step)	0	0x5	0x0	0x0	Family 5 Model 0

Family 4

Microarchitecture	Core	Extended Family	Family	Extended Model	Model	Family • Model
Intel 486 (80486)	Intel 80486	0	0x4	0x0	0x9	Family 4 Model 9
	Intel 486DX4	0	0x4	0x0	0x8	Family 4 Model 8
	Intel 80486	0	0x4	0x0	0x7	Family 4 Model 7
	Intel 80486	0	0x4	0x0	0x5	Family 4 Model 5
	Intel 486SL	0	0x4	0x0	0x4	Family 4 Model 4
	Intel 486DX2	0	0x4	0x0	0x3	Family 4 Model 3
	Intel 486SX	0	0x4	0x0	0x2	Family 4 Model 2
	Intel 486DX	0	0x4	0x0	0x1	Family 4 Model 1

Family 3

• 80386