System Upgrade Specifications:
Type of Memory:	667MHz DDR2 ECC fully-buffered
Standard Memory :	1Gb ( 2 x 512MB)
Memory Expansion Slot:	8 Slots (4 on each riser card)
Memory board sizes:	1GB,2GB, 4GB
Memory added @ time	Two (2)

Upgrade Tips : The MacPro two 3GHz Quad-Core Intel Xeon ships with 1Gb (2 x 512Mb). Machine has Two riser cards with 4 memory sockets on each riser card. Memory must be added in pairs ( one module per socket on each riser card).Main memory of the system can be upgraded to 32Gb [maximum]. Trans International complies with Apples' thermal specification for the Mac Pro Memory. A heat sinks is added to 667MHz DDR2 ECC fully buffered DIMMs (FB-DIMMs) for more efficient cooling. These FB-DIMMs require less airflow to stay cool and allow the internal fans to spin at slower speeds, improving system acoustics. FB-DIMMs made by other manufacturers that do not include a sufficient heat sink may cause the fans to run faster (and louder) or the memory chips to run slower so as not to overheat. To take full advantage of the 256-bit wide memory architecture, four or more memory modules should be installed.