Hi guys. My power mac G5 is an old late 2005 quad core model. ECC; briefly this is me Standard Configuration for Apple Power Macintosh G5 Late 2005 QuadCore 2.5GHz DDR2 ECC (M9592LL/A) and i have NEVER bought any ram before coz i hardly used the machine in those days, so what i have so far are 2 of these: 1 GB DDR2 SDRAM EEC PC2-4200E-444. So i am going to buy 16GBs of new ram in 4GB pieces; so can i purchase this typ of ram? 4GB kit (2GBx2), 240-pin DIMM, DDR2 PC2-6400 memory module CT785039 * Module Size: 4GB kit (2GBx2) * Package: 240-pin DIMM * Feature: DDR2 PC2-6400 * Specs: DDR2 PC2-6400 CL=6 Unbuffered ECC DDR2-800 1.8V 256Meg x 72 at http://www.crucial.com/store/mpartspecs.aspx?mtbpoid=205ECD41A5CA7304 OR must I purchase a DDR2 PC2-4200E444 exactly the same as what i have? I just wanna know whether the PC2-6400 module makes any difference, it wont blow up my mac will it? Cheers guys.