You can see in the pictures here that this card has x16 pci-e but says it only requires one 6pin and one 8pin connection to work in the description of requirements.
http://media.sapphiretech.com//images/prods/2065/11221-07_R9_280X_GDDR5_DP_HDMI_2DVI_PCIE_C05_635200436536258218_600_600.jpg
Can I plug the 6pin into one of the 8pin slots safely?
From this: [ : : : : ] [ : : : : ] (not connected)
to looking like this when fully plugged in as required?
[ : 8 8 8 ] [ 8 8 8 8] (connected)
http://media.sapphiretech.com//images/prods/2065/11221-07_R9_280X_GDDR5_DP_HDMI_2DVI_PCIE_C05_635200436536258218_600_600.jpg
Can I plug the 6pin into one of the 8pin slots safely?
From this: [ : : : : ] [ : : : : ] (not connected)
to looking like this when fully plugged in as required?
[ : 8 8 8 ] [ 8 8 8 8] (connected)