• ALU Arithmetic Logic Unit
• AGU Address Generation Unit
• FPU Floating Point Unit
• SIMD Single Instruction Multiple Data
• MMX MultiMedia eXtensions
• SSE Streaming SIMD Extensions
• SSE2 Streaming SIMD Extensions 2
• SSE3 Streaming SIMD Extensions 3
• SSSE3 Supplemental SSE3
• SSE4 Streaming SIMD Extensions 4
• AVX Advanced Vector Extensions
• ISA Instruction Set Architecture
• IPC Instructions Per Cycle
• CPI Cycles Per Instruction
• ILP Instruction-Level Parallelism
• MLP Memory-Level Parallelism
• OoO Out-of-Order
• OOOE Out-of-Order Execution
• SMT Simultaneous Multithreading
• HT Hyper-Threading
• µop / uop Micro-operation
• µcode Microcode
• TLB Translation Lookaside Buffer
• ITLB Instruction TLB
• DTLB Data TLB
• BTB Branch Target Buffer
• BPU Branch Prediction Unit
• RSB Return Stack Buffer
• RAS Return Address Stack
• LFB Line Fill Buffer
• MSHR Miss Status Holding Register
• MTRR Memory Type Range Register
• PAT Page Attribute Table
• WC Write Combining
• WT Write Through
• WB Write Back
• UC Uncacheable
• WC+ Enhanced Write Combining
• MESI Modified Exclusive Shared Invalid
• FSB Front Side Bus
• APIC Advanced Programmable Interrupt Controller
• LAPIC Local APIC
• IOAPIC I/O APIC
• MSR Model Specific Register
• PMC Performance Monitoring Counter
• PMU Performance Monitoring Unit
• PEBS Precise Event-Based Sampling
• BTS Branch Trace Store
• LBR Last Branch Record
• CPUID CPU Identification Instruction
• MWAIT Monitor Wait
• CMPXCHG Compare and Exchange
• CAS Compare And Swap
• SMC Self-Modifying Code
• CISC Complex Instruction Set Computer
• RISC Reduced Instruction Set Computer

Misc P6-related abbreviations

• RS - Reservation Station
• EU - Execution Unit
• FEU - Floating Point Execution Unit
• IEU - Integer Execution Unit
• WIRE - Miscellaneous Functions
• JEU - Jump Execution Unit
• AGU - Address Generation Unit
• ROB Reorder Buffer
• RAT Register Alias Table
• RRF Retirement Register File
• RS Reservation Station
• BAC Branch Address Calculator
• BHT Branch History Table
• RSB Return Stack Buffer
• DCU Data Cache Unit
• BIU Bus Interface Unit
• IFU Instruction Fetch Unit
• MITE Micro-Instruction Translation Engine
• uROM Microcode ROM
• IEU Integer Execution Unit
• FEU Floating-point Execution Unit
• ATC Advanced Transfer Cache
• MOB Memory Order Buffer
• ARF Architectural Register File
• PRF Physical Register File