[dave49er]

MDD (Mirrored Drive Doors) 2002 & 2003 and FW800 (FireWire 800) Models.
* Compatible with Mac OS 9.2.2 and OS X Version 10.2 and Higher
* 3 Year Limited Warranty
* Powered by Two Freescale (formerly Motorola) G4 7455B Processors
* Tested and Guaranteed at 1.33GHz for both 133MHz and 167MHz System Bus Power Mac Models
* 256KB L2 Cache Per Processor Operating Dual 1.33GHz G4 7455 Processor Upgrade Recommended for PowerMac at Full Processor Speed
* 2MB L3 Cache Per Processor Operating at 1/6 the Processor Speed

Product:
http://www.gigadesigns.com/index.asp...&ProdID=19

Install Guide:
http://www.gigadesigns.com/index.asp...stom&ID=18

Previously they had a Dual 7447 for the MDDs that was pulled for reliability reasons. These are 7455 chips.
I have a MDD FW800 Dual G4 867 (originally single 1.0GHz) with (I think) 256KB L2 Cache and 1MB L3 Cache per processor.
How would this compare speedwise?

[Lateralus]

Originally Posted by dave49er

Previously they had a Dual 7447 for the MDDs that was pulled for reliability reasons.

Negative.

There was never an upgrade from the 7447 family available for the MDD machines. And all of GigaDesigns' 7447 offerings for the other Power Mac product families have never had any reliability issues so I'm not sure what you're thinking of.

This upgrade is a returning product, BTW. It had been available from Giga a few years ago but was pulled due to slow sales. Now that MDDs are old enough for their owners to start looking toward newer machine purchases, Giga has brought it back in an attempt to lure them.