iMac and SSD. USB 3.0 or Thunderbolt 2?

[gthm]

Hi,

I have a late 2014 iMac with 2 Thunderbolt 2 ports and 4 USB 3.0 ports.

My sessions are very light but slow, even though on an SSD (Samsung T3 USB-3.1 to 3.0 SSD).

My sample, VI drive is a Glyph Blackbox Pro HDD. (too slow?)

I am looking to upgrade my sample, VI drive.

It is between the Glyph Atom Thunderbolt 3 SSD or the Samsung T5 USB 3.1 SSD.

Question: which one would be faster for my setup?

1) Glyph Atom Thunderbolt 3 SSD, with Thunderbolt 3 to 2 adapter?

or

2) Samsung T5 USB 3.1 SSD, with USB-C to 3.0 cable?

Should I utilize my second, unused Thunderbolt 2 port (the first Thunderbolt 2 port is taken by my audio interface, Apogee Ensemble Thunderbolt), or just get a regular Samsung T5 USB 3.1/3.0 SSD and be done?

Would there be a big difference between Thunderbolt 2 and USB 3.0 basically?

Let me know guys!

Thanks_