The natural progression of the low-power Deschutes family of Pentium II processors to the portable PC market took place with the launch of the Mobile Pentium II range in April 1998. The new processor, and its companion Mobile 440BX chipset, were initially available at 233MHz and 266MHz, packaged in the existing Mobile Module (MMO) or an innovative mini-cartridge package, which contained the processor core and closely coupled 512KB Level 2 cache. The mini-cartridge was about one-fourth the weight, one-sixth the size and consumed two-thirds of the power of the Pentium II processor desktop SEC cartridge, making it well-suited for a broad range of mobile PC form factors, including thin, lightweight, ultraportable systems.
The 233MHz and 266MHz Pentium II processors for mobile PCs were manufactured on Intel’s 0.25-micron process technology and offered the same performance-enhancing features as the existing Pentium II processors for the desktop segment, including: Dual Independent Bus architecture, Dynamic Execution, MMX technology and a closely coupled 512KB Level 2 cache. The mobile Pentium II processor system bus operated at 66MHz. Additionally, to address the unique thermal requirements of mobile PCs, the new mobile Pentium II processor contained built-in power management features that helped manage power consumption and improve reliability.
The mobile Pentium II processors, which operated at an internal core voltage of 1.7V, were Intel’s lowest voltage mobile processors introduced to date. The 233MHz processor core generated 6.8 watts TDP (thermal design power) typical and the 266MHz version consumed 7.8 watts TDP typical. With the addition of the second level cache, the 233MHz mobile Pentium II processor operated at 7.5 watts, while the 266MHz version operated at 8.6 watts.
At the end of January 1999 Intel launched a new family of Mobile Pentium II processors, codenamed Dixon. The key development was the location of the Level 2 cache, which was moved onto the die and accelerated from half the core CPU speed to full speed. Although the new CPUs – available in clock speeds of 333MHz and 366MHz – had 256KB of Level 2 cache, rather than the 512KB of previous Mobile Pentium IIs, overall cache efficiency was enhanced about threefold thanks to its faster speed and proximity to the CPU.
As well as retaining the existing mobile module and mini-cartridge packaging, making it easy for vendors to upgrade, the Dixon was also available in a new smaller, thinner and lighter Ball Grid Array (BGA) package. At less than a 10th of an inch high this was one-third the size and half the height of the mini-cartridge, allowing it to fit in mini-notebooks, which had hitherto been restricted to the ageing Mobile Pentium MMX family. A key benefit of the single-die implementation was reduced power consumption, battery life being the key requirement of a portable PC. The 336MHz mobile Pentium II processor operated at an internal core voltage of 1.6V and, according to Intel, consumed around 15% less power than existing Mobile Pentium IIs at the same clock speed.
By mid-1999 the Mobile Pentium II was available in speeds up to 400MHz. The 400MHz part was notable for being Intel’s first processor built using an 0.18-micron manufacturing process. Also available built on 0.25-micron technology, the 400MHz Mobile Pentium II was available in four packaging options – mini-cartridge, BGA, micro PGA and the Intel Mobile Module – and contained 128KB of integrated L2 cache.