Intel Pentium 4 SL5N8 1.5GHz 256KB 400MHz FSB 1.75V Socket 478 P4 CPU

Intel Pentium 4 SL5N8 1.5GHz 256KB 400MHz FSB 1.75V Socket 478 P4 CPU

This is an Intel Pentium 4 desktop processor with the SL5N8 S-spec designation, running at 1.5GHz with a 400MHz front side bus. It uses the Socket 478 interface and is built on Intel's Willamette core using a 180nm manufacturing process. The label on the chip reads 1.5GHz/256/400/1.75V and the SL5N8 code is clearly printed, confirming the exact stepping.

Specifications & What's Included

• Brand: Intel
• Processor family: Pentium 4 (Willamette core)
• S-Spec / MPN: SL5N8
• Clock speed: 1.5 GHz
• Front side bus (FSB): 400 MHz
• L2 cache: 256 KB
• Core voltage: 1.75V
• Socket: Socket 478 (mPGA478B)
• Manufacturing process: 180nm
• Number of cores: 1
• Country of manufacture: Costa Rica (visible on label)
• CPU only — no heatsink, fan, or retention bracket included

Applications

The Intel Pentium 4 Socket 478 processor family was Intel's mainstream desktop CPU platform from roughly 2001 through 2004. The 1.5GHz Willamette was among the first Socket 478 releases, introduced in 2001 as Intel transitioned from the earlier Socket 423 form factor to the longer-lived Socket 478 standard. These processors powered entry-level to mid-range desktop PCs of the era and are compatible with a wide range of Socket 478 motherboards using chipsets such as the Intel 845, 850, and 845E. The Willamette core used a 180nm process and 256KB L2 cache; later Socket 478 Northwood-core chips moved to 130nm and 512KB cache, making the early Willamette stepping the more collectible of the two for vintage PC restorers. Today this processor is sought by collectors building period-correct early-2000s systems, retro gaming rigs, or restoring legacy workstations that require a Socket 478 CPU. It is also useful as a direct replacement part for any Socket 478 board that supports Willamette-generation processors.