|  |  
        
        
           
            | Option # | Top Level Part #
 | Manufacturing Part #
 | Option Description | Substitute Part #
 |   
            | X7023A | 595-3870 | 501-2654 
              [F] (128MB) | 1 GB (8 × 128MB DIMMs) | n/a |   
            | X7026A | 595-5405 | 501-5658 
              [F] (256MB) | 2 GB (8 × 256MB DIMMs) | n/a |   
            | X6738A | 595-5139 | 375-0087 
              [F] | 32MB Fast Write Cache | n/a |   
            | X7021A [S] | 595-3868 | 501-2652 
              [F] (8MB) | 64 MB (8 × 8MB DIMMs) | n/a |   
            | X7022A [S] | 595-3869 | 501-2653 
              [F] (32MB) | 256 MB (8 × 32MB DIMMs) | n/a |  
           
            | Table Legend |   
            | [F] = Field Replaceable 
              Unit (FRU) [S] = Supported, but can no longer be ordered 
              with this system
 [N] = No longer supported for this system
 |  |