The Intel Pentium III 1266S was a desktop processor with 1 core, launched in July 2001. It is part of the Pentium III lineup, using the Tualatin architecture with Socket 370. Pentium III 1266S has 512 KB of L2 cache and operates at 1266 MHz. Intel is building the Pentium III 1266S on a 130 nm production process using 44 million transistors. The multiplier is locked on Pentium III 1266S, which limits its overclocking capabilities.
With a TDP of 30 W, the Pentium III 1266S consumes only little energy. Although the processor doesn't come with integrated graphics, certain motherboards with compatible chipsets can provide this capability.
Many games will refuse to start on this processor due to the lack of the SSE2/SSE3/SSE4 instruction set.