The extra 1MB of backside cache only saved 7 seconds, literally no gain in this test. Other than Virtual PC and Unreal, most applications showed little gain from the extra 1MB of backside cache. Benchmark Tests Benchmark tests were run with MacBench 5.0 as it is the accepted Mac standard. I've also included results with two memory bandwidth benchmarks which show somewhat disappointing results. Remember the most important results are the real world applications performance above.
Benchmarks have their place, but actual applications performance is what really matters.
The base system ran OS 9, 320MB of Interleaved RAM, VM Off, and OpenGL 1.1.2 with its ATI driver update. All G4 tests had the 4 OS 9 Altivec extensions active and Photoshop 5.5 used Adobe's latest Altivec core extension and Lighting Effects Plugin. Some explanation of the MacBench graph and test components. MacBench CPU scores for the G4 upgrades were lower than I expected and less than a 350MHz G3. These G4 upgrades however seemed to have lower than normal FPU scores, again perhaps to the 'write-through' cache mode.