INTEL

Intel Pentium III 866

Intel processor specifications and benchmark scores

1
Cores
1
Threads
GHz Boost
38W
TDP
🖥️Integrated GPU

Intel Pentium III 866 Specifications

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Pentium III 866 Core Configuration

Processing cores and threading

The Intel Pentium III 866 features 1 physical cores and 1 threads, which directly impacts multi-threaded performance in CPU benchmarks. More cores allow the processor to handle parallel workloads efficiently, improving performance in video editing, 3D rendering, and multitasking scenarios. Thread count determines how many simultaneous tasks the CPU can process, with higher thread counts benefiting productivity applications and content creation workflows.

Cores
1
Threads
1
SMP CPUs
1
⏱️

Pentium III 866 Clock Speeds

Base and boost frequencies

Clock speed is a critical factor in Pentium III 866 benchmark performance, measured in GHz. The base clock represents the guaranteed operating frequency, while the boost clock indicates maximum single-core performance under optimal conditions. Higher clock speeds translate to faster single-threaded performance, which is essential for gaming and applications that don't fully utilize multiple cores. The Pentium III 866 by Intel can dynamically adjust its frequency based on workload and thermal headroom.

Base Clock
866 GHz
Boost Clock
N/A
Multiplier
6.5x
💾

Intel's Pentium III 866 Cache Hierarchy

L1, L2, L3 cache sizes

Cache memory is ultra-fast storage built directly into the Pentium III 866 processor die. L1 cache provides the fastest access for frequently used data, while L2 and L3 caches offer progressively larger storage with slightly higher latency. Larger cache sizes significantly improve CPU benchmark scores by reducing memory access times. The Pentium III 866's cache configuration is optimized for both gaming performance and productivity workloads, minimizing data fetch delays during intensive computations.

L1 Cache
8 KB
L2 Cache
256 KB
🏗️

P6 Architecture & Process

Manufacturing and design details

The Intel Pentium III 866 is built on Intel's 180 nm manufacturing process, which determines power efficiency and thermal characteristics. Smaller process nodes allow for more transistors in the same space, enabling higher performance per watt. The architecture defines how the processor handles instructions and manages data flow, directly impacting benchmark results across different workload types. Modern CPU architectures like the one in Pentium III 866 incorporate advanced branch prediction and out-of-order execution for optimal performance.

Architecture
P6
Codename
Coppermine T
Process Node
180 nm
Foundry
Intel
Transistors
44 million
Die Size
80 mm²
Generation
Pentium III (Coppermine T)
🔢

P6 Instruction Set Features

Supported CPU instructions and extensions

The Pentium III 866 by Intel supports various instruction set extensions that enable optimized performance for specific workloads. SIMD instructions like SSE and AVX accelerate multimedia, scientific computing, and AI workloads by processing multiple data points simultaneously. Features like AES-NI provide hardware-accelerated encryption, while AVX-512 (if supported) enables advanced vector processing for data centers and high-performance computing. These instruction sets are critical for software compatibility and performance in modern applications.

MMX
SSE
🔌

Pentium III 866 Power & Thermal

TDP and power specifications

The Intel Pentium III 866 has a TDP (Thermal Design Power) of 38W, indicating the cooling solution required for sustained operation. TDP affects both system power consumption and the type of cooler needed. Lower TDP processors are ideal for compact builds and laptops, while higher TDP chips typically offer better sustained performance in demanding CPU benchmarks. Understanding power requirements helps ensure your system can deliver consistent performance without thermal throttling.

TDP
38W
🔧

Intel Socket 370 Platform & Socket

Compatibility information

The Pentium III 866 uses the Intel Socket 370 socket, which determines motherboard compatibility. Choosing the right platform is essential for building a system around this processor. The socket type also influences available features like PCIe lanes, memory support, and upgrade paths. When comparing CPU benchmarks, ensure you're looking at processors compatible with your existing or planned motherboard to make informed purchasing decisions.

Socket
Intel Socket 370
Package
µPGA
DDR5

Intel Socket 370 Memory Support

RAM compatibility and speeds

Memory support specifications for the Pentium III 866 define which RAM types and speeds are compatible. Faster memory can significantly improve CPU benchmark performance, especially in memory-intensive applications and gaming. The memory controller integrated into the Pentium III 866 determines maximum supported speeds and channels. Dual-channel or quad-channel memory configurations can double or quadruple memory bandwidth, providing noticeable performance gains in content creation and scientific workloads.

🖥️

Intel's Pentium III 866 Integrated Graphics

Built-in GPU specifications

The Intel Pentium III 866 includes integrated graphics, eliminating the need for a dedicated GPU in basic computing scenarios. Integrated graphics are ideal for office productivity, video playback, and light gaming. While not designed for demanding GPU benchmarks, the iGPU in the Pentium III 866 provides hardware video encoding and decoding capabilities. This makes the processor suitable for compact builds, HTPCs, and systems where power efficiency is prioritized over gaming performance.

iGPU
On certain motherboards (Chipset feature)
Graphics Model
On certain motherboards (Chipset feature)
📦

Pentium III 866 Product Information

Release and pricing details

The Intel Pentium III 866 is manufactured by Intel and represents their commitment to delivering competitive CPU performance. Understanding the release date and pricing helps contextualize benchmark comparisons with other processors from the same generation. Launch pricing provides a baseline for evaluating value, though street prices often differ. Whether you're building a new system or upgrading, the Pentium III 866 by Intel offers a specific balance of performance, features, and cost within Intel's product lineup.

Manufacturer
Intel
Release Date
Jun 2001
Market
Desktop
Status
End-of-life
Part Number
SL5QESL5HG

Pentium III 866 Benchmark Scores

📊

No benchmark data available for this CPU.

About Intel Pentium III 866

The Intel Pentium III 866 delivers a classic single‑core architecture that remains relevant for legacy systems and low‑power office workstations. Built on a 180 nm process, the Coppermine T core features a 866 MHz clock speed while maintaining a modest 38 W TDP, making it suitable for environments where heat and energy consumption are concerns. With its Intel Socket 370 interface, the Intel Pentium III 866 can be installed in a wide range of existing motherboards without requiring major hardware changes. Performance metrics focus on integer and floating‑point operations typical of early‑2000s productivity applications, offering reliable throughput for word processing, spreadsheets, and basic database tasks. Although benchmark data is unavailable, the processor’s design emphasizes stability and compatibility rather than raw speed. The price bracket for this vintage CPU is typically found in the budget or collector’s market, providing an economical option for retro‑computing projects. When considering upgrades, users should evaluate the benefits of moving to newer architectures that support multi‑core processing, higher clock rates, and advanced power‑saving features.

  • Chip design: 1‑core, 180 nm Coppermine T with 866 MHz clock.
  • Performance metrics: Adequate for legacy office applications, low TDP.
  • Price bracket: Budget-friendly in the vintage and collector segment.
  • Upgrade considerations: Assess modern multi‑core alternatives for improved efficiency.

The AMD Equivalent of Pentium III 866

Looking for a similar processor from AMD? The AMD Ryzen 5 1400 offers comparable performance and features in the AMD lineup.

AMD Ryzen 5 1400

AMD • 4 Cores

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