P2 CPU "class, " but 386/486 ISA "core" are commonplace -- AMD5x86 = 486 ISA

[Bryan J. Smith]

Bryan J. Smith wrote:  
> Cyrix had the same issues.  Not only was the Cyrix 5x86 also only a 486
> ISA, but the 6x86 through P200+ (150MHz) was _still_ a 486 ISA.

Leonard den Ottolander wrote:
> Hi Bryan,
> FYI P200+ = 166 MHz.

Not the original Cyrix 6x86.
They all had a fixed 2.0x multiplier.

 55MHz * 2 = 110MHz (P133+)
 60MHz * 2 = 120MHz (P150+)
 66MHz * 2 = 133MHz (P166+)
 75MHz * 2 = 166MHz (P200+)

Yes, the original Cyrix 6x86-P200+ ran the PCI and ATA beyond
spec, or at async on select chipsets.

The latter 6x86"L" and M2s stuck with a 66MHz FSB, including for
the P200+.  I believe they were 66MHz * 2.5x.


-- 
Bryan J. Smith, E.I. -- b.j.smith at ieee.org