Performa 600 and Mac IIvx, Road Apples

Road Apples are Apple’s most compromised hardware designs. For the most part, they’re not completely bad – simply designs that couldn’t meet their potential. The Performa 600 is more deserving of the Road Apple title than any Mac before it, as is it’s nearly identical twin, the Mac IIvx.

Macintosh IIvxWhile the “compromised” Macs based on the LC motherboard achieved 70-75% of their potential while running a 32-bit CPU on a 16-bit bus, the IIvx achieved as little as 55% of its potential by running a 32 MHz CPU on a 16 MHz bus. Ouch! And the Performa 600 was even worse, since it didn’t include a level 2 cache or support adding one.

One way to make a cheaper computer is to use slower components. Apple designed the IIvx with a 32 MHz 68030 CPU – and a 16 MHz motherboard. A stock Mac IIci with it’s 25 MHz 68030 outperforms the IIvx by 30%; adding a level 2 cache (usually 32 KB in those days) made the IIci even faster. In fact, the old 16 MHz Mac IIx outperforms the IIvx on some benchmarks!

The IIvx benchmarks at 2.7. Compare this with 2.9 for the 16 MHz IIx, 3.5 for the 25 MHz IIci (4.3 with cache), and 6.8 for the 40 MHz IIfx. Had the IIvx used a 32 MHz data bus, it would have benchmarked at about 5.0.

With a few too many compromises, the IIvx was less than expected and a hard sell against the more powerful IIci, at least for those who understood the differences. This is the oldest Mac to merit the Road Apple designation.

The best thing about the IIvx/Performa 600 and their 16 MHz sibling, the IIvi, is that they can be upgraded to a Quadra 650 or Power Mac 7100 by swapping the motherboard.


  • introduced September 1992
  • requires System 7.1 to 7.6.1
  • CPU: 32 MHz 68030
  • FPU: 68882 (optional on Performa 600)
  • performance, P600: 5.8, Speedometer 3; 0.44, Speedometer 4; 6.5 MIPS
  • performance, IIvx: 2.7 (relative to SE; 16 MHz IIx rated 2.9, 25 MHz IIci at 3.5)
  • RAM: 4 MB on motherboard, expandable to 68 MB using lone 4-SIMM bank of 80ns 30-pin memory; can use 256 KB, 1 MB, 2 MB, 4 MB, and 16 MB SIMMs
  • built-in 8-bit video with 512 KB VRAM, supports 512 x 384 at 16-bits, 640 x 480 at 8-bits, and portrait monitor (640 x 870) at 4-bits
  • L2 cache: 32 KB on IIvx (not supported on Performa 600)
  • PDS slot supports L2 cache only in IIvx, accelerator card in both models
  • ADB: 2 ports for keyboard and mouse
  • serial: 2 DIN-8 RS-422 ports on back of computer
  • SCSI: DB-25 connector on back of computer
  • three NuBus slots

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