Is using one 6+2 connector on the split cable the same as using a dedicated single 6+2 cable?
For the sake of relevance(and sanity), you might want to elaborate on this. Are you referring to the pigtail/daisychain connector off a 6+2 pin? Might want to include the make and model of your PSU and it's age and what GPU you're trying to hook it up to.