The Pentium II incorporates many of the salient features of the Pentium Pro and Pentium MMX; however, its physical package was based on the SECC/Slot 1 interface and its 512 KB L2 cache ran at only half the processor internal clock rate. First generation Pentium II Klamath CPUs operated at 233, 266, 300 and 333Mhz with a FSB of 66Mhz and a core voltage of 2.8 Volts. In 1998, Intel introduced the Pentium II Deschutes that operated at a speed of 350, 400 and 450 MHz with a 100 Mhz, and later 66MHz, FSB and at 2.0 Volts at the core. Its major improvements were:
q 16 Kb L1 instruction and data caches
q L2 cache with non-proprietary commercially available SRAM
q Improved 16 bit capability through segment register caches
q MMX unit.
q Standard Pentium II could only be used in dual multiprocessor configurations; however, Pentium XEON cpus had up to 2 MB of L2 cache and could be used in multiprocessor configurations of up to 4 processors.