I’ve got a Ultra II 960 with same firmware…
I have this SSD Partitioned into 4 drives… Speedtest on 3 are about the same, but boot (C drive) is half as fast as other drives… Don’t know why…
I tried the restart issue, and mine remains 6Ghz speed of disc buss… but speedtests report same (C: half as fast).
Dell i7 XPS 1702x A19 Bios W7-64