Single/Dual Fan GPUs

In theory, two fans can do more work(cooling) than one fan. So then they can spin slower while keeping the card just as cool= less noise. In real life this may or may not be significant because maybe the card doesn't run hot to begin with. Personally, I'd go with the dual fans unless space was an issue.

Separately, the SC is the slightly lower end model, with the SSC being slightly higher end. So the SSC might have better components in general(ACX 3.0). It doesn't mean the SC isn't good, it's just noting a difference between the two cards besides the fact one has a single fan and the other is dual fan.