Memory Option # Manufacturing Part # Description Previous Part # SEWX2B2Z-N 4 × 2GB DDR2-667 Memory Expansion X-option F371-4801 [F] 2GB DDR2-667 DIMM, n/a SEWX2C2Z-N 4 × 4GB Memory Expansion X-option F371-4802 [F] 4GB DDR2-667 DIMM, n/a SEWX2D2Z-N 4 × 8GB DDR2-667 Memory Expansion X-option F371-4803 [F] 8GB DDR2-667 DIMM, n/a SEWX2A1Z [S] 4 × 1GB Memory Expansion X-option, L 371-4343 [F] 1GB DIMM, n/a SEWX2B1Z [S] 4 × 2GB Memory Expansion X-option, L 371-4344 [F] 2GB DIMM, n/a SEWX2B2Z [S] 4 × 2GB DDR2-667 Memory Expansion X-option, L F371-4801 [F] 2GB DDR2-667 DIMM, n/a SEWX2C1Z [S] 4 × 4GB Memory Expansion X-option, L 371-4345 [F] 4GB DIMM, n/a SEWX2C2Z [S] 4 × 4GB DDR2-667 Memory Expansion X-option, L F371-4802 [F] 4GB DDR2-667 DIMM, n/a SEWX2D1Z [S] 4 × 8GB Memory Expansion X-option, L 371-4591 [F] 8GB DIMM, n/a