Still waiting for mine to arrive—sometime after August 22 I am told.
Just a quick follow up on the low 4K QDxx numbers ... The max I was able to achieve was 266MB/s read and 78 MB/s write and that was only when I chose the option to run the test 6 times in a row.
As I suspected, this is a hardware limitation - specifically, memory and cpu speeds. Your 5,1 is spooling its 1333MHz system memory / L3 cache and processing concurrent requests at least twice as fast as a 3,1.
Overall, I am super satisfied with the increase in speeds and responsive of the system after the NVMe upgrade. Boot, single/multi application, processing, file copy and loading times have improved so much that I am no longer considering upgrading to a new system for at least 2 more years.
Thanks again for sharing this find.