FPU built in CPU - whether the co-processor (if present) is built-in or external.

Virtual Mode Extensions - (VME) CPU supports the extensions for V86 mode that typically enhances the speed of virtual machines under Windows.

Debugging Extensions - (DE) CPU supports breakpoint setting in the I/O address space.

Memory Page Size Extensions - (PSE) The standard page size is 4KB. Some processors may support different sizes (4MB) which is advantageous when more memory is installed.

Time Stamp Counter - Internal counter incremented every clock cycle that allows high precision measurements.

Model Specific Registers - (MSR) CPU has special (model-specific) internal registers.

Physical Address Extension - (PAE) Physical addresses bigger than 32-bits are supported.

Machine Check Exception - (MCE) Exception 18 is supported.

CMPXCHG8B Instruction (64 bit compare) - (CX8) An instruction to compare & exchange 8 bytes.

Multiprocessor support (APIC enabled) - An Advanced Interrupt Controller is built-in which is faster and can be used for multi-processing.

Fast System Call supported (SYSENTER/SYSEXIT) - (FSC) Support for instructions SYSCALL & SYSRET.

Memory Type Range Registers - (MTRR) Supports special registers that improve cache throughput.

Global Page Enable - (GPE) CPU supports global pages enable/disable.

Machine Check Architecture - (MCA) Internal test of processor is available.

CMOV Instruction - (CMOV) Allows conditional execution of instructions without jumps.

Serial Number - (PSN) CPU has an unique serial number that is visible to software.

MMX - Multi-Media extensions is s set of instructions added by Intel to speed-up multimedia applications by using SIMD (single instruction multiple data) type operation like multi-processor arrays.

AMD Extended 3DNow! - Extensions added to MMX by Cyrix & AMD.

AMD 3DNow! - this is a set of instructions added by AMD to speed-up 3D multimedia applications using the processor. Unlike MMX, it works with floating point data. Support is included in DirectX 6 and later.

IntelStreaming SIMD extension - A superset of MMX set of instructions added by Intel to speed-up multimedia applications by using SIMD (single instruction multiple data) type operation like multi-processor arrays. While MMX works with integer data, SSE works with floating-point data. Support is included in DirectX 6.1 and later.

MMX is an extension to the x86 instruction set that allows multiple bytes of data to be packed together in a single register and operated on simultaneously. MMX consists of 57 new instructions for speeding multimedia tasks. The trick to these new instructions is that they operate on many different data elements at once, which increases the overall amount of work the processor can do. Examples range from operating on multiple pixels in a bitmapped image to multiple sound channels in an audio stream. MMX is not intrinsically a graphics or multimedia acceleration technology, but those are the types of applications that stand to benefit most. MMX will provide a substantial performance boost for some new applications that are coded to use MMX (more so for home rather than for business applications).

SSE(2) is an extension to the MMX instruction set designed to accelerate software performance in application that use 3D graphics, 3D geometry, signal processing, simulation, video and 3D software rasterisation, video encoding/decoding (e.g. MPEG, MPEG2).