Intel Pentium III 533B & 600B

The Pentium III 533 and the 600B are both based on the same 0.25 micron core that all of the previous Pentium III processors were based on. Keep in mind that these are not the Coppermine processors that we have been waiting so long for. Hopefully, those chips will be out within the next month or so.

The chips still feature the same 32KB L1 cache and 512KB L2 cache (operating at ½ clock speed) as their predecessors. In fact, the only difference between these two chips and those that have come before them is that the Pentium III 533 uses a 4.0x clock multiplier and the Pentium III 600B uses a 4.5x clock multiplier. This is because these are 133MHz FSB processors and thus use lower clock multipliers to achieve their clock speeds. Intel could have just taken a regular Pentium III 600 and reprogrammed the multiplier lock to default to 4.5x instead of 6.0x and they’d have a 600B. As usual, both processors are clock multiplier locked at the respective multipliers.

It seems like Intel is having some problems pushing the Pentium III to 600MHz, which explains why the core voltage on the Pentium III 600 is actually 2.05v and not the standard 2.0v. The same is true for the Pentium III 600B, whose 2.05v core voltage is necessary for proper operation. Unfortunately, this leaves the Pentium III 600 (and the 600B) as an essentially overclocked processor, since the core was designed to operate at 2.0v not at the 2.05v Intel has spec’d the latest CPU at.

The Pentium III 533 operates at the same 2.0v core voltage as all of the other Pentium III processors so there are no problems here. Your motherboard will have no problem supplying either the 2.0v or 2.05v core voltage to the processor provided that you are using the latest BIOS.

Keep in mind that unless you are using these processors on a motherboard with official support for the 133MHz FSB, you won’t be able to use them at their intended frequencies since they use lower clock multipliers than the 100MHz FSB Pentium IIIs. Remember, there is no difference between the Pentium III 533/600B and the regular Pentium III other than "official" support for the 133MHz FSB and lower clock multipliers at equivalent clock frequencies.