Umax SuperMac C500

The UMAX SuperMac C500 and C600 were the first "Power Macs" with the processor in a ZIF socket, making upgrades very easy. Having a C500/200 at work, and finding an incredible garage sale special on upgrades from Small Dog Electronics, I decided to test the 240 MHz upgrade and the Cache Doubler.

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

MacBench 5

The system was tested on 14 December 1999 under Mac OS 7.6.1 with a basic installation. Computer attached to a 17" color monitor and tested in 8-bit video mode at 640 x 480 resolution. The disk cache was set to 2 MB for all tests. The drive was not optimized before benchmarking. Results are relative to a Power Mac G3/300 (beige), which scores 1000. The C500 would not run the graphics tests due to limited VRAM.

test      CPU   FPU  disk  graphics
200 MHz   273   383   607    n/a   
240 MHz   293   424   623    n/a   
240x2     462   435   687    n/a   

Moving from a 200 MHz processor to 240 MHz, one would expect about 20% higher CPU and FPU figures, but we see only a 7% improvement on the CPU score and 11% on floating point math.

Replacing the standard 40 MHz 256 KB motherboard cache with the 80 MHz 1 MB Cache Doubler module makes a substantial difference on CPU score - it's 58% higher than before, and an impressive 69% faster than the stock 200 MHz processor.

Floating point scores increase slightly, indicating the FP part of MacBench isn't closely coupled to cache size.

An interesting improvement with Cache Doubler - the Western Digital Caviar 12100 hard drive scores 10% higher, while moving from 200 to 240 MHz had less than a 3% impact on drive performance.

Overall, the improvement is quite impressive, especially considering the blow-out pricing on these discontinued upgrades.

If you have a C500 or C600 with a slower processor (200 MHz or less), or even a faster CPU without Cache Doubler, visit Small Dog Electronics to see if they have any left in stock. As I write this, the 603e/240 processor sells for $29, the Cache Doubler for 200 or 240 MHz CPU for $9, and the Cache Doubler for the 280 MHz for $29.

For information on installing the Cache Doubler in the C500, see our installation guide.