I promised to get back with the Aja test results for my various RAID 5 set ups.
I originally had a RAID 5 x4 4TB HDDs in the MP internal 3GB/s bays. I purchased an OWC Mercury Elite Pro Quad Ext. case w/ USB 3.1 Gen2.
I also had a 4-port
Sonnet Allegro Pro (SAP) USB3 (Gen1) PCIe card and then purchased a 4-port
Sonnet Allegro Pro USB-C (Gen2) PCIe card. Installed the new PCIe card into Slot #4.
I only used one USB port so that no secondary drives were sharing simultaneous bandwidth (except a USB3 hub with only peripherals attached).
x4 4TB HDD Read/Write Aja results:
- RAID 5 in Internal cMP Bays - 390/280
- RAID 5 in OWC Gen2 case using SAP Gen1 card - 185/165
- RAID 5 in OWC Gen2 case using SAP Gen2 card - 410/410
- RAID 1+0 in OWC Gen2 case using SAP Gen2 card - 300/330
- RAID 0 in OWC Gen2 case using SAP Gen2 card - 595/665
I was somewhat happy with the RAID 5 - Gen2 results until I reformatted to RAID 0. I knew it would be faster but not that much faster. Of course, I realize if one drive fails, the RAID 0 fails. I have a couple of backup 4TB drives that I pulled as they were getting old and could re-install one, re-format the RAID 0 and clone my backup drive until a new 4TB drive arrives. With approx. 400/400 speeds, cloning 5.8TB of files takes about 4.5 hours on my MP.
Speaking of my backup drive. It is a x2 6TB RAID 0. Originally installed in an OWC USB 3 Gen1 case and consequently moved to the MP internal bays when I transferred the x4 4TB HDDs to the external case.
x2 6TB HDD Backup Drive Read/Write Aja results:
- RAID 0 in OWC Gen1 case using SAP Gen1 card: - 240/190
- RAID 0 in OWC Gen1 case using SAP Gen2 card - 245/190
- RAID 0 in Internal cMP bays - 370/370 (compare these results with the original RAID 5 internal bay results above)
I don't mind using RAID 0 as a backup. I have a third backup using Backblaze in case something happens before a replacement 6TB drive arrives.
I hope all this provides some insight. (And a testament to my tech geekiness!)
(MP 5,1, 6-core 3.46ghz, 48GB RAM, Samsung 970 EVO NVME, Radeon 7950 GPU, Mojave 10.14.3)