any pci or pci-e video card.
such as ATI Radeon video cards (not agp ones) or NVidia GeForce video cards (again, excluding the agp ones)
No sorry the Dell Optiplex 780 can't support a i7, it would have to be a 1155, 1156, 1366 socket compatible motherboard, but your options would be a Intel Core 2 Quad like a Q6700, upwards. Your Dell has a 775 socket.
280 + 500 = 780
780
The Dell OptiPlex 780 Ultra Small Form Factor (USFF) does not inherently support redundant network cards or connectivity through its standard configuration. While it may have options for adding network functionality via USB or PCIe adapters, true redundancy typically requires specific hardware support or configurations that are not standard in the USFF model. For advanced networking solutions, consider looking at higher-end models or dedicated network equipment designed for redundancy.
780
35% of 780= 35% * 780= 0.35 * 780= 273
45% of 780= 45% * 780= 0.45 * 780= 351
150% of 780= 150% * 780= 1.5 * 780= 1170
55% of 780 = 55% * 780 = 0.55 * 780 = 429
780
78
The multiples of 780 (which are infinite) are all divisible by 780, including these: 780, 1560, 2340, 3120, 3900, 4680, 5460 . . .