Apple has had some amazingly closed systems, some with not quite enough expansion, and a few that had so many expansion options that the mind boggles. This article takes a brief look at the most expandable Macs every by CPU.
The Ulti-Mac 68030: Mac IIfx
This one is a no-brainer. The Mac II, IIx, and IIfx all have six NuBus expansion slots, but the “wicked fast” IIfx runs at 40 MHz with fast 32 KB level 2 (L2) data cache. It uses an uncommon 64-pin SIMM for memory that allows faster access than conventional SIMMs and can both be read and written to simultaneously. It has SCSI DMA, a first for the Mac, and can handle an incredible 128 MB of memory.
The IIfx originally sold for $10,000 and up depending on the configuration. That price did not include a video card or a keyboard, although the mouse was included. You must add at least one video card, but that leaves you with five more to fill.
The Mac II was originally designed for a 5.25″ hard drive, so there’s room for several 3.5″ SCSI hard drives if you get creative.
As if all of that wasn’t enough, the Mac IIfx also has a 40 MHz 68030 Processor Direct Slot (PDS), so you could potentially put in a 68040 or PowerPC accelerator.
The Ulti-Mac 68040: Quadra 950
It wasn’t the fastest 68040-based Mac – that honor goes to the Quadra 840av clocked at 40 MHz. The 840av was fast and expandable, but its 3 NuBus slots mean that it has less expansion options than the Quadra 900 and 950, both of which have 5 NuBus slots plus a 68040 PDS. (The 840av has no PDS, but for video work, it has a special place in Mac history.)
The Quadra 900 and 950 have three half-height internal drive bays plus two drive bays up front to hold CD-ROM and other types of removable media drives. There are 16 memory slots, and you can install up to 256 MB of memory.
Unlike the IIfx, these Quadras have integrated video, so you don’t need to put a video card in one of the NuBus slots.
The Quadra 950 takes the nod here, because it runs at 33 MHz vs. the Quadra 900 being clocked at 25 MHz. Both are equally expandable, but speed is the tie-breaker. For a bit more speed, you can put an L2 cache in the PDS, and for even more power, Apple also made a PowerPC 601 upgrade card that plugs into the PDS. The ultimate Q950 accelerator was the Sonnet 100 MHz PowerPC 601 Presto PPC.
The Ulti-Mac 601: Apple Workgroup Server 9150
Built inside the same case as the Quadra 950, the Workgroup Server 9150 was available with a PowerPC 601 CPU running at 80 MHz – and it was later speed bumped to 120 MHz. (This is the only Workgroup Server without an equivalent Macintosh model.) It has four NuBus slots and a PDS.
It’s biggest drawback is probably that it uses system memory for video, and it has 8 MB of RAM on the system board. You can add up to 256 MB of memory (for 264 MB total) using 8 72-pin SIMMs.
Internal video only supports up to 832 x 624 resolution (Apple’s way of one-upping 800 x 600 SVGA in the PC world), so between that and video using system memory, you might want to consider adding a nice accelerated NuBus video card.
The Ulti-Mac 604: Power Mac 9600
Six PCI slots. Need I say more? Both the Power Mac 9500 and 9600 offer that many slots, but the 9600 takes the win with a more accessible case and up to a 350 MHz PowerPC 604e CPU or dual 200 MHz processors (which only helped with software specifically written for multiple CPUs, since the Classic Mac OS itself cannot use a second CPU).
The best feature of the Power Mac x500 and x600 series is that the CPU resides in a daughter card, so it can be easily replaced by something even more powerful – say a G3 or G4 CPU!
The 9600 supports a whopping 1.5 GB of system memory and shipped with the ixMicro TwinTurbo video card, which was pretty state-of-the-art in those days. With the video card in one PCI slot, you still have five more that you can fill with whatever.
The Ulti-Mac G3: Power Mac G3 Blue and White
This one was a tough call, because the Beige Power Mac G3 had built-in SCSI, a floppy drive, and Apple serial ports, making it more backward compatible in some ways than the Blue and White. But the Blue and White takes the win with 4 PCI expansion slots (one at 66 MHz for faster video), support for 1 GB of RAM (vs. 768 MB), and a faster drive bus – 33 MBps ATA-4 instead of 16 MBps ATA-2.
Apple offered the Blue and White in speeds ranging from 300 MHz to 450 MHz on a 100 MHz system bus (vs. 66 MHz on the Beige G3). There are issues with the Revision A logic board only supporting one boot drive; if you plan on having two bootable ATA hard drives, be sure to get Revision B.
This was the first Power Mac with built-in USB and without built-in SCI, although Apple sold a SCSI card for those who wanted it. It also introduced FireWire to the Mac world.
This was the last Power Mac with a built-in ADB port. Going forward, everything would be USB.
Editor’s note: This was a previously complete article pulled out of our draft archives from 2018.
