Giga Designs: When faster isn't faster


Giga Designs has posted a webpage describing the relative merits and drawbacks of upcoming G4 upgrades for MDD P'Macs. Here's their spin:

Thank you for your interest in an upgrade for the Apple MDD Power Macs based on the Freescale (formerly Motorola) 7447A microprocessor. At this time we are in product development for this upgrade, but will not plan to release this product until 1.8GHz+ processors are available from Freescale.

From the tests we have performed to date with the 133MHz bus AGP equipped Power Macs, we have determined the performance of a 7447A processor running at 1.733GHz to be equivalent to that of a 7455 running at 1.467GHz. The 7447A does not support an L3 cache, and in most applications requiring a heavy CPU load [ie many games] this has a big impact on performance. Our recent dual-7455 based MDD upgrade (running at 1.42GHz in a 167MHz bus MDD or 1.4GHz in a 133MHz bus MDD) offers a better overall value at $629 when compared with a dual 7447A running at 1.733GHz which we would need to sell at $799 based on our current 7447A chip pricing.

Although the 7447A boasts a 40-percent reduction in power over the 7455 [emphasis added], this does not benefit the MDD Power Macs with their 360W power supplies. The AGP (Sawtooth) and Cube Power Macs shipped with power supplies rated at 200W and 208W respectively, and therefore the reduction in power is beneficial to owners of these systems who wish to upgrade their processor(s), in addition to their graphics card and storage devices.

Of course, you'll need to consider this information when choosing an upgrade for your Sawtooth through Quicksilver tower, or G4 Cube. At this point, a lower-speed chip and more affordable chip looks like the best options for owners legacy PowerMacs.

What's your take?