Just because Thunderbolt might be able to theoretically move 10Gbps or whatever the spec is, doesn't mean it can or will - that will depend on the hard drives. One or two drives are not going to have the same throughput as a 24 drive RAID array. Meaning Thunderbolt and USB 3.0 will likely both have the same throughput in your situation, being limited by what the drives can do. Both connections may well exceed the capacity of the drives.
And what kind of footage are you editing? Uncompressed HD? ProRes 422? AVCHD or DSLR footage? Lots of variables to consider.
Does the external 8TB have 2 drives or 4 drives in it? If it's a 4-drive, then it ought to be faster than 2-drive internal RAID.
Safe Harbor Computers
Thanks for the quick reply,
The footage is from the Canon 300 (MXF) 4K
I was "hoping" that the two cables will give the same performance, but what workflow would be better?
Meaning, the SATA connection to a internal Drive or Thunderbolt to an external? (assuming both drives perform the same)
I keep thinking about the specs.
SATA =6G /sec
Thunderbolt =10 G/ sec
The 6Gbs for Sata is per channel which would be each port. Thunderbolt is 10Gbs per channel or 20Gbs for TB2 but your only dealing with 1 port for the entire drive set. Internal Sata is also lower latency so the internal Sata raid would be faster and better. Keep in mind until you exceed the bandwidth availalble for Thunderbolt the only real difference will be latency unless the storage controller in the TB unit is poor. That is another factor though that could reduce the Thunderbolt drive performance.