Due to a bug in the Quartus II software, the .pin file reports that the transceiver VCCR_GXB supply needs 1.2v on Arria V GX -C4, -C5, -I3 and -I5 devices for datarates >3.2Gbps on Arria V GX devices.
The correct voltage for VCCR_GXB when using transceivers running at >3.2Gbps on Arria V GX -C4, -C5, -I3 and -I5 devices is 1.15v as detailed in the Arria V GX Pin Connections Guidelines document.
This issue will be fixed in a future version of the Quartus II software.