so..
in retrospect 5 models only..
the only g4 macs that had 2MB L3 CACHE:
ranked from slowest to fastest cpu power:


single cpus:
-G4 867 (QS) (2001)             133mhz bus >>> 487
-G4 933 (QS) (2002)             133mhz bus >>> 550

dual cpus:
-G4 800 DP (QS) (2001)        133mhz bus >>> 670 (335 per?)
-G4 1.0 DP (QS) (2002)         133mhz bus >>> 854 (427 per?)
-G4 1.25 DP (MDD) (2002)    167mhz bus >>> 1078 (539 per?)


so in conclusion the 2002 1.25ghz dual processor MDD is the fastest stock os9 computer ever made
the only 167mhz bus + only one with both 2MB L3 Cache as well as ATA-100 disk speed access
on the main IDE bus

addendum:
ive just rechecked the fact that the Sonnet Encore (Single) CPUs feature level 3 cache up to the 1.4ghz models
here are the infos / part numbers from the pdf:


SG4-1000-2M  1.0 GHz 256KB 2MB
SG4-1200-2M  1.2 GHz 256KB 2MB
SG4-C1200 1.2 GHz 256KB 2MB
G4-1400-2M 1.4 GHz 256KB 2MB
not sure what the diff is between the two 1.2ghz models
with this new (old) information.. does this mean the 1.4ghz sonnet is the fastest single g4 cpu that also has 2MB L3 Cache?
perhaps.

**** remember these SONNET cpu upgrades being compatible with 100mhz + 133mhz fsb g4s EXCLUDING the MDD of course:
Power Mac G4 (AGP Graphics)
Power Mac G4 (Gigabit Ethernet)
Power Mac G4 (Digital Audio)
Power Mac G4 (QuickSilver 2001)
Power Mac G4 (QuickSilver 2002)
Power Mac G4 Cube*
Macintosh Server G4

perhaps this whole "Cube" enthusiast movement relies heavily on the fact that the g4 cube could be upgraded to 1.4ghz sonnet cpu with 2mb l3 cache