15 Years Ago Motorola Unveiled the PowerPC G3

On February 6, 1997, Motorola unveiled the CPU code named "Arthur" and destined to be known as the G3 when Apple began using the CPU in November 1997. Unlike earlier PowerPC CPUs, the G3 was optimized for the real world, especially the Mac OS and Mac software. Because of these efficiencies, the G3 provided almost twice as much processing power as a PowerPC 604e - the chip used in top-end Power Macs - at the same clock speed. The end results were killing off the market for most 604e-based pro Macs and laying the foundation for the later G4 and G5 CPUs.

"Arthur represents the first time Somerset has optimized a new core based primarily on extensive execution of Mac OS applications."

The original G3 (a.k.a. PowerPC 750) had been designed to replace the 603e CPU used in consumer and notebook Macs. Compared with the 603e, it had a faster system bus, larger onboard caches, added a second integer unit (which the 604e already had), improved floating point processing, and added branch prediction (also in the 604e). All of these contributed to its improved performance, and a side benefit was that the new CPU was also more powerful than the pro-oriented 604e. Much of this is detailed in "Arthur Revitalizes PowerPC Line" by Linley Gwennap (PDF), published Feb. 17, 1997.

Beige Power Mac G3

Dan Bashur (Apple, Tech, and Gaming): The G3 era was when I really got into the vast majority of Macs I have worked with/on and have used on my own. Dad got a Beige G3, and it was incredible in comparison to anything else we had used before, but time and time again, I have recollected to my colleagues how much I was blown away when my favorite computer lab at Ohio State transitioned from 80 Power Mac 7100/80AV units to the same number of G3 Blue and White machines.

Blue & White Power Mac G3

The Blue and Whites looked modern, sleek, and almost beckoned out - Use me! With its unforgettable large G3 logo on the side of the tower and processing speed that was light years ahead of the 7100, it was more than an upgrade. It felt like a reinvention of the wheel. It also shipped with FireWire, and although it couldn't use Target Disk Mode, I can remember the lab guys there being blow away by how fast the transfer rate was - and I can see why. Going from 11 Mbps USB 1.1 to 400 Mbps FireWire ushered in a whole new era of high-speed peripherals, and when Target Disk mode was enabled on newer models, it offered a new way to transfer data between Macs.

Graphite iMac G3

As much as I was blown away by the B&W G3 tower lab, the original iMacs and iBooks were what really heated up the G3 era, and I had always wanted one or the other. I wound up settling on a 600 MHz Summer 2001 Graphite iMac G3 due mainly for the desire of the included CD-RW drive (which at the time was a very expensive component itself). Too bad I didn't see the writing on the wall with the forthcoming flat panel Luxo iMac G4 just four months later, but my CRT iMac G3 stayed in service for seven years (until it was replaced by a 1.42 GHz eMac as my main Mac for the next couple of years), and it still boots up just fine today - more than a decade later - still problem free! It proved to be one of the very last G3 Macs, but it was certainly one of the best with a much improved PPC 750cx compared to earlier G3 750 chips.

15 years have gone by since the advent of the G3, and it has been more than 14 years since the first Macs implemented the PPC 750, yet it can be argued that they are still relevant today. 12-year-old Pismos are still in service running 400 and 500 MHz G3 processors. Just ask Charles Moore, myself, Austin Leeds, or other LEM staffers and fans. The G3 was very stable and reliable, and in most cases was not soldered, providing access to G4 upgrades (such as the 500 and 550 MHz G4s still offered for the Pismo), further extending the life of the product.

Many consider the G3 and G4 era to be the "Golden Age" of Macs, where earth shattering changes in product design and technology implementation dominated (while providing maximum compatibility with better and better releases of Mac OS) versus incremental differences. Incredible quantities of these Macs are still in service today and can still be quite useful running Mac OS X 10.4 Tiger - even with modern Core "i" processors on the scene.

The 1998 WallStreet PowerBook G3.

Charles Moore (several columns): Moving up from a 100 MHz 603e to a 233 MHz G3 13 years ago was like crossing into another dimension. I actually cut my G3 teeth on one of the Level 2 cache-less "MainStreet" G3 Series PowerBooks in the fall of 1998. Even that much-maligned machine, which also was Apple's last laptop with a passive matrix LCD display, was so much livelier than my then 3-year-old PowerBook 5300.

I was a local sales agent for a Mac reseller in another part of the province at the time, and the MainStreet 'Book was my demo. We sold more of those PowerBooks than any other Mac models during that venture - except the ones people actually bought were all equipped with active matrix (TFT) displays and the full G3 with L2 cache, including the one I bought myself in January, 1999. That 12" 800 x 600 resolution screen (essentially the same one used in the first generation Clamshell iBook) seems almost toyish now, but it was like the wide open spaces compared with the 9.5" 640 x 480 resolution passive matrix grayscale display of the PowerBook 5300 I was migrating from.

However, the G3's most impressive attribute was its speed, and that 512 KB of L2 cache gave it plenty by the standard of the day. You could actually multitask with it at reasonable levels of efficiency, and remember this was in the days before Mac OS X brought real preemptive multitasking to the Mac.

My next G3 machine was a used Pismo PowerBook that I bought in 2001 and still have in active service, although it's long-since been upgraded to 550 MHz G4 power. Its original 500 MHz G3 CPU offered a nice performance boost over the 233 MHz WallStreet, but nothing nearly as dramatic as the first G3s were compared with the 603 and 604 machines. My last G3 was a 700 MHz iBook I bought new in 2002, but it never seemed much, if any, quicker than the 500 MHz Pismo, which had a larger L2 cache.

I no longer have a working G3 Mac, as both of my current Pismos have G4 upgrades, but I found the 500 MHz 750 chip a surprisingly good performer running OS X 10.4 Tiger before I upgraded the most recent unit, and I remember the G3 processor with great affection and nostalgia. It was truly a watershed in the Mac's evolution.

Simon Royal (Mac Spectrum): My first experience of the Mac was on an old Quadra at a publishing house. The whole department was upgraded to G4s, and as the new comer to the department I was given a 600 MHz Graphite iMac - to me it was amazing. It's speed was phenomenal even in the dawn of the G4 range.

I took home a Beige G3 tower that had been replaced by a G4, and this gave me a huge opportunity to get my teeth into the whole Mac experience. Using an iMac G3 running OS X 10.2 Jaguar at work was amazing, but coming home to a Beige G3 running OS 9 started to frustrate me, so I bought an 400 MHz Indigo iMac G3, and the rest is history.

Having owned over 30 Macs and being a big low-end Mac user, the G3 range has given me some of my most beloved and reliable Macs. While outdated, the ultra reliable PowerBook G3 range make awesome superstrong portable writing machines, and an iMac G3 still looks awesome in any house.

The G3 with it's awesome power, coupled with the gorgeous looks of the iMac G3, made it iconic and pulled Apple from the brink.

Dan Knight (Mac Musings): I first used a Mac in late 1986, and I remember how exciting the Mac II was with its 16 MHz 68020 CPU and color support. It more than doubled processing power, and we really haven't seen that big a jump in performance since then. The 68040-powered Quadras were a big step forward in efficiency, but the first Quadras also ran at lower clock speeds than the top-end 68030 Macs, so while we saw an improvement, it wasn't stellar. The same goes for Apple transitioning to PowerPC as well as moving from the first-generation PPC 601 to the 603 and 604.

The G3 was probably the biggest improvement in Mac CPU technology since the Quadra. The 266 MHz Beige Power Mac G3 outperformed the 350 MHz 604e in the top-end Power Mac 9600, quite a breakthrough - and the kind of thing we wouldn't see again until the Mac went from Core 2 Duo Intel CPUs to its more efficient Core i family.

I worked in publishing at the time, and our production machines were mostly Power Mac 7500s and 8500s. The first Beige G3s were a revelation, especially for things like Quark XPress, FrameMaker, and Photoshop. Apple was able to ride the G3 from late 1997 through late 2003, when the last G3 iBook was replaced by a G4 version.

And quite frankly, the G4 was just a G3 with the Altivec velocity engine added and better support for multiple processors. Likewise, the G5 made some improvement to system bus speed and clock speed, but the underlying architecture was just an evolutionary improvement to the G3 that Motorola had unveiled in February 1997, an architecture that carried the Macintosh through the end of the PowerPC era.

Best of all, a lot of those old G3s can still be useful with enough memory and OS X 10.4 Tiger installed. I don't think I'd want to run anything below 400 MHz, but get into the 500-700 MHz range, and you've got some nice iMacs and iBooks to pick from, not to mention the beloved Pismo.