Dubious results - RAID 0 tests same as single HDD

I have a 27” 2011 iMac that I use only for video editing, mostly in 1080p but with some UHD and 4K video. I use several single-disk drives attached to my iMac via USB 3.0 for tasks that aren’t speed-intensive, as well as a 2-disk G-RAID configured in RAID 0 (and connected via USB 3) for my video files. I recently added a Seagate Expansion 5TB drive to use as an archiving location for video media that I no longer need to edit with. I downloaded BM Disk Speed Test because I was curious about the relative read/write speeds of my Seagate and Western Digital USB 3 drives, as well as my 4TB G-RAID in RAID 0 configuration.

The results of the tests with this app were surprising, and I wonder about their accuracy. Briefly, the Seagate and WD USB 3 drives had pretty much identical stats; the WD is 80% full, while the Seagate is ~ 25% full, but perhaps this test wouldn’t catch performance difference between drives because of fullness. What was surprising is that the RAID 0 drive had the same stats as the single-disk drives: 10-bit YUV 4:2:2 HD1080 write: 5-6, read: 6-7.

The checkbox that’s supposed to (simplistically) tell you if editing will “work” tells me that all the drives can work for SD editing only, not HD (1080P), and there’s no difference between the RAID 0 drive and the single disk drives. Well, the G-RAID does indeed work for editing 4:2:2 1080p video shot on my Sony FS7, but the WD and Seagate drives fall short in their throughput for video editing. That’s my real-world experience, and it’s not surprising at all, but this app gets it wrong.

It doesn’t make sense that this app pulls similar stats for my single-platter hard drives and the 2-disk RAID 0, both connected via USB 3.

Nikosuave about Blackmagic Disk Speed Test