The Dell Precision 5810 has three options for power supply wattage. 425 watt, 685 watt, and 825 watt. The power supply itself does not have a 6 pin power connector, but all Precision 5810 chassis have a Power Supply extended card. This card supports two 6 pin connections that are commonly needed for video cards (Figure 1 - 3).
Power supply extended card:
Figure 1
Card location:
Figure 2
6 pin cable splitter:
Figure 3
If you have further questions about this information, please contact Dell Technical Support.