Connection requirements for DSD playback

What is the right chain of connections for the computer output and DAC input to play DSD files? Does the USB out from the computer have to be 2.0? Does a DAC to SPDIF or I2S conversion help? I just want to know if my computer limits DSD file output merely by not having updated digital outs. I have both PC and Mac. I understand that straming software also has to be DSD compatible, but that is easier to figure out. Obviously, the DAC should be able to handle DSD. However, it gets complicated with the possibility of DSD over PCM. What kind of upgrade would make that possible? My DAC is an early Wyred 4S DAC-2. Thanks!