Hex Core Model: 3.33Ghz. INSIDE YOUR MAC PRO HEX CORE. below is link that shows every compatible Xeon CPU, its details each CPU and its maximum supported ram size/speed. Your Mac Pro has 4 slots and the maximum possible upgrade is 56GB (3x16GB + 1x8GB) or 64GB (4x16GB) depending on what CPU you have installed .
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