For those paying attention, I relocated my graphics card in my Vision D from the 8x slot to the 16x slot. To do so I had to replace the Sabrent heat sink with the much smaller Gigabyte provided one in order to keep the Windows NVMe in the first NVMe socket. I also relocated the PCI SATA interface Catalina boots from to the 8x PCI slot. Doing all this borked the Windows boot device settings presumably because I had installed the Gigabyte Intel storage drivers that messed with the BIOS. Rewinding to the latest Windows restore point solved that, but I'm not on the "fancy" storage drivers now. I ran the Crystal bench again, and now instead of 2500 read/write, it's now 3400/3150. It's not the 5000 read/write commonly reported on Amazon for the Sabrent, but it's progress. The real question is why it got better. I'm thinking the location of the NVMe and the PCI cards are not acting as described in the manual. The speeds reported before are exactly what you might expect if the NVMe was sharing with someone. Others report the speeds cut by half when they combine things the manual states are shared resources. Except in my case the manual indicated I was not sharing any resources. Moving things around should not have improved anything. But it did???? I would still like to get the NVMe up closer to 5000 if possible, just "because". And the question remains if I want to reinstall the Gigabyte Rapid Store driver 17.9.0.1007? I'm not using any RAID function. The NVMe does appear in BIOS as Intel Rapid Store, and Windows claimed at one point you could not uninstall once it's installed.
During the test the NVMe reached about 62C. Otherwise it seems to run at about 54C.
And quit bitching at me about this referencing Windows. I'm dual booting Mac/Win, and I feel this is relevant for a lot of use cases found here. Windows gives you visibility into things at the hardware level, and the Mac does too. It's not 100% overlap. And even the OP mentions dual booting Windows.