Mac IIsi

The IIsi uses RAM for video, which it takes from the 1 MB of memory on the motherboard. This creates a use-of-memory conflict between video and system software, reducing performance. IIsi-RAM-Muncher by Paul Ripke addresses this by preventing the system from using the first megabyte of memory. As the benchmarks below demonstrate, IIsi-RAM-Muncher provides a real performance boost.

The drive, an 80 MB Apple-branded Quantum ProDrive LPS, was formatted with Apple HD SC Setup 7.3.5. The drive was tested with Norton and optimized before benchmarking.

Remember that benchmarks are arbitrary. They measure certain types of performance that may or may not reflect the way you work.

Speedometer 3.06

The system was tested on 2 October 1998 under System 7.5.5 with all inessential extensions off. Computer attached to a portrait monitor and tested in both 1-bit and 4-bit video modes. Results are relative to a Mac SE or Classic, which rates 1.0. Numbers rounded off to two decimal places.

The first set of numbers compares performance at different cache settings.

cache  video  munch?  CPU  graphics  disk   math
 32KB  4-bit    no    3.84   5.42    2.08   3.90
 64KB  4-bit    no    3.84   5.46    2.07   3.96
128KB  4-bit    no    3.84   5.40    2.11   3.90
256KB  4-bit    no    3.84   5.40    1.88   3.90

The cache setting should have little influence on non-disk tests, which these numbers bear out. With this particular setup, cache size makes no appreciable difference through 128KB, then drops.

The second set of numbers compares performance at different video settings and with IIsi-RAM-Muncher.

cache  video  munch?  CPU  graphics  disk   math
 64KB  1-bit    no    5.03   6.98    2.11   5.40
 64KB  1-bit   YES    5.28   7.22    2.12   5.71
 64KB  4-bit    no    3.84   5.46    2.07   3.96
 64KB  4-bit   YES    5.26   6.10    2.17   5.70

These results show that the IIsi runs 28-36% faster on the CPU, graphics, and math tests with 1-bit video than in 4-bit mode.

The big surprise is that with IIsi-RAM-Muncher, CPU and math performance are virtually identical at both video settings - and IIsi-RAM-Muncher makes an even bigger difference than switching from 4-bit to 1-bit.

Speedometer 4.02

The system was tested on 2 October 1998 under System 7.5.5 with all inessential extensions off. Computer attached to a portrait monitor and tested in both 1-bit and 4-bit video modes. Results are relative to a Quadra 605, which rates 1.0. Numbers rounded off to two decimal places.

The first set of numbers compares performance at different cache settings.

cache  video  munch?  CPU  graphics  disk   math
 32KB  4-bit    no    0.24   0.30    0.82   0.55
 64KB  4-bit    no    0.24   0.31    0.80   0.55
128KB  4-bit    no    0.24   0.30    0.81   0.55
256KB  4-bit    no    0.24   0.30    0.73   0.55

The cache setting should have little influence on non-disk tests, which these numbers bear out. As above, with this particular setup, cache size makes no appreciable difference up to 128KB. At 256 KB it drops 10%, which is unexpected.

cache  video  munch?  CPU  graphics  disk   math
 64KB  4-bit   yes    0.32   0.32    0.85   0.83
 64KB  4-bit    no    0.24   0.31    0.80   0.55

Speedometer 4 shows no perceptible difference at different video settings. Improvement due to IIsi-RAM-Muncher is similar to that found under Speedometer 3.