OK So a very interesting G4 CPU Upgrade came my way this week...The OWC Mercury Extreme G4 (Speeds from 900Mhz. to 1.467Ghz.)Mercury Extreme G4 upgrade offers 256Kb of 1:1 L2 cache on-chip and 2MB of L3 cacheAlso, The Mercury Extreme G4 also includes a pre-installed, high-performance heat sink and a pair ultra-quiet cooling fans

After installing countless Giga Designs, PowerLogix, and Sonnet CPU Upgrades over the years for clients, this baby deserves an honorable mention; like all 7455 upgrades, It require
no system firmware patch at all. As Mactron has mentioned, 7447A, 7448 and 7457s are a different story.
So I bought a G4 QS off ebay (even though I own 5) for the sole purpose of getting the Mercury Extreme G4. The entire tower (with the originally 933 in a bag) and the OWC G4 upgraded installed was only $80... lol... so how could I resist.
I had only read about these, but they were always rare and pricey. It works on many G4 towers, AGP Graphics (Sawtooth), Gigabit Ethernet, DA, and QS Towers (both 100Mhz and 133Mhz. Buses)

Even when the prices were dropped in 2004, they still cost a few bucks...
New pricing on all the Mercury Extreme upgrades is: US$329.99 (was $349.99) for the 1GHz model; $399.99 (was $419.99) for the 1.25-1.33GHz model; $439.99 (was $449.99) for the 1.25-1.4GHz model; $499.99 (was $539.99) for the 1.4-1.467GHz model; and $529.99 (was $549.99) for the 1.4-1.5GHz model.
All the Mercury Extreme G4 upgrades are compatible with Power Mac G4 AGP Graphics (Sawtooth), Gigabit Ethernet, Digital Audio and Quicksilver models and support Mac OS 9.2.1 and higher, as well as Mac OS X and higher, including v.10.3.x "Panther." Each processor upgrade comes with a three-year warranty and a 30-day 100 percent money-back guarantee.[/size]
This baby boots and runs flawlessly (at the full balls out 1.467Ghz.) in OS 9 with a 480GB OWC SSD (that I added), I will be posting more info about this very fast, very quiet G4 Upgrade.
Install Manual:
https://eshop.macsales.com/tech_center/manuals/mercuryextreme/OWCMEG42.pdfOne interesting note is that the Original QS case fan (near the CPU) is removed all together ! This actually makes the G4 quieter since the Upgrade CPU pair of fans are less noisy than the original single fan.
Made with the highest-quality components available, the Mercury Extreme uses Tantalum-dipped resistors and capacitors (to resist electroshock discharge), is capable of safe operation at high temperatures, and is designed to last longer than other upgrade processors using conventional parts. "Since the Mercury Extreme G4's custom heat sink/fan system actually operates cooler than the competition, we used heat-resistant parts to further increase reliability and lifespan," O'Connor said. "Not only is our heat sink greatly improved over other heat sinks designed for older processors, but our system also includes a cooling fan which directs air across the heat sink for optimum cooling without simply pushing air against it. The fan is also whisper quiet and does not add to system noise."