Performance Test C 10.0.20 vs Logic Pro 10.4.5 vs Studio One 4.5

As my internal HD in the iMac is 7200rpm and the new to arrive is an external Thunderbolt SSD I was thinking about putting it as my boot disk with High Sierra installed then having my projects and samples reside on the internal 7200rpm. What do you think of that idea?
If I had more $ I’d get an internal SSD but … you know.