^{1 When stacking the DGS-3130-30TS/30S/30PS models, the stacking cost is 1 per unit so the maximum units per stack is 9. When stacking the DGS-3130-54TS/54S/54PS models, the stacking cost is 2 per unit so the maximum units per stack is 6. When stacking different models in the same stack, switches can be stacked up to a maximum of 12 stacking cost per stack. For example: 2 x DGS-3130-30TS (2 stacking cost) + 2 x DGS-3130-30S (2 stacking cost) + 4 x DGS-3130-54TS (8 stacking cost) consumes a total stacking cost of 12 (2+2+8).}