What is the difference between the pentium processor and the pentium II processor?

A 1.13 GHz version was released in mid-2000 but famously recalled after a collaboration between HardOCP and Tom's Hardware discovered various instabilities with the operation of the new CPU speed grade. The Coppermine core was unable to reliably reach the 1.13 GHz speed without various tweaks to the processor's microcode, aggressive cooling, additional voltage (1.75 V vs. 1.65 V), and specifically validated platforms. Intel only officially supported the processor on its own VC820 i820-based motherboard, but even this motherboard displayed instability in the independent tests of the hardware review sites. In benchmarks that were stable, performance was shown to be sub-par, with the 1.13 GHz CPU equalling a 1.0 GHz model. Tom's Hardware attributed this performance deficit to relaxed tuning of the CPU and motherboard to improve stability. Intel needed at least six months to resolve the problems and re-released 1.1 GHz and 1.13 GHz versions in 2001.