Technical Specifications

Q. What bus speed is the K6-2 speced for?

A. The K6-2 is shown to its best advantage when running in a Super Socket 7 board. This means that it handles the exciting new 100MHz front side bus. It works equally well, although noticeably slower, in the older 66MHz motherboard designs.

The K6-2-266 is officially being released as a 66MHz bus speed processor (that’s 66MHz x 4 = 266MHz). It seems to work fine at 100MHz x 2.5= 250MHz. Many people are pushing these parts to 100MHz x 3 = 300MHz (although AMD does not officially recommend overclocking their processors).

The K6-2-300 is officially being touted as a 100MHz bus speed processor (that’s 100MHz x 3 = 300MHz). It seems to work fine at 66MHz x 4.5 = 300MHz as well.

Q. What are the voltage requirements for the K6-2?

A. The official voltage requirements for the K6-2-266 and K6-2-300 parts are 2.2V inner core (+/- 0.1V) and 3.3V outer core (+/- 0.1V). Some of the earliest motherboards that claimed support for the K6-300 have a 2.1V inner core setting. This may work, but has proven problematic for some owners for earlier revisions of some boards. The K6-2 will also not tolerate too high a voltage on the inner core. Pushing up the inner core in hopes of overclocking success can help, but is not recommended for those who need the ultimate in stability and reliability. 

Q. How overclockable are these K6-2 chips?

A. The K6-2 chips are fairly overclockable, but within limits.  There have been many success stories of K6-2-266 chips easily overclocking to 300MHz.  Since the K6-2-266 is officially only a 66MHz FSB, it's ability to sometimes go to 300MHz (3x100Mhz) can be seen as significant overclocking. 

The K6-2-300 chips are only occassionally able to make it to 350MHz (3.5 x 100MHz).  This may change with more robust motherboard designs, but don't expect miracles here.  For every email I received relating a success story, I've had two that couldn't achieve 350MHz reliably.  Upping the core voltage of the chip from the recommended 2.2V to 2.4 or 2.5V may help, but don't be shocked if it's a no go.   Users must realize overclocking is not a given.  The available margin of performance is typically lot dependant.  Some production lots have very high yields capable of outstanding overclocking performance.  More often then not, the lots' performance is reasonable and well within spec, but the headroom to achieve awesome overclocking is never guaranteed.   

Q. What's the story on the upcoming K6-2-333?

A. The K6-2-333 is unique in that it isn't really a 100MHz FSB chip.  AMD found that pushing the K6-2-300 to 350MHz wasn't a very reliable thing to do.  So they slowed down the bus speed from 100MHz to 95MHz and applied a 3.5x multiplier (3.5 x 95MHz = 333MHz).   This seems to be a reasonable setup and one that the K6-2-300 chips handle quite well.  Since they're slowing down the bus speed down to 95MHz this will slow down the access to the memory system (not a great thing), but speed up the processor speed (a good thing).  The effective difference appears to be about a 5 to 6% speed increase from the K6-2-300 (100MHz FSB) to the K6-2-333 (95MHz FSB).  The only motherboards that seem to support this are custom modified by AMD as demo systems.  This will certainly change in the ensuing months.