Ah, now all of this is beginning to make sense. BUT if the SATA drives only deliver 500 MB/sec at RAID 0, then it shouldn’t have really mattered if initially I was plugged into the USB 3.1 rather than the thunderbolt, right? (assuming I wasn’t using any of the other ports, which I wasn’t)
For the last couple of weeks, I was doing fine with my thunderbolt to thunderbolt. And then, out of the blue yesterday, the drive was super-laggy. I had to wait for it to get up to speed and play over, and over, and over… There was even a delay while I waited for it to copy a puny little photo file from my desktop to the LaCie.
The fact that you are a frequent LaCie user makes me think:
1) you’ve never had lag problems with your drives; and
2) maybe mine is flawed and should be sent back for a replacement!
Beyond being a 4K project, the thing I’m working on is super-basic. Quicktime H264 and MXF files. Stringing together soundbites. That’s it.