The reason for Intel marketing CPUs that operate at two different front side bus speeds at the same time is understandable when you factor in the push to introduce their first mainboard core logic chipsets that operate at the faster speed (i810e, i820).

Without CPUs on the market that can handle a 133MHz bus speed, and are configured clock multiplier-wise to match their core's MHz rating, Intel's new mainboard core logic sets would have no possible market to sell to.

It's likely that in a perfect world Intel would have liked their .18 micron Coppermine CPUs to launch simultaneously with their new 133MHz core logic sets, particularly the i820, but that goal ended up being optimistic and an alternative plan had to be pursued as the launch dates approached.

That alternative plan consists of the P3-533B and P3-600B CPUs, which will serve to bridge the gap between the existing 100MHz Katmai CPUs and the upcoming 133MHz Coppermine processors.

Ironically, it appears now that the i820 core logic set actually will debut simultaneously with several Coppermine CPUs in late October, thanks to a recent RDRAM-based delay that Sharky Extreme covers in depth in our first i820 mainboard review.

For now, buyers who wish to operate their systems at a 133MHz bus speed will need three specific items:

• A mainboard that's capable of selecting and handling the 133MHz bus speed.
• PC-133 SDRAM, although most PC-100 SDRAM we've seen the past two months can handle 133MHz without a problem.
• An Intel CPU that's set to operate at a 133MHz bus speed, which consists solely of the P3-533B and P3-600B at the moment. (100MHz-class Intel P3s can only achieve a 133MHz bus speed if grossly overclocked, which is not a guaranteed solution.)

The best part of the list above is the fact that if the user decides they want to upgrade later on to an i820 mainboard when they finally arrive, all they'll need to do is swap out the 440BX or i810e mainboard itself and plug in the new i820 board.