Intel NVMe drivers performance going down ?

@Fernando ,$
I use an i750 400 GB PCIe NVMe card for now two years on different W10 x64 PCs.
I have updated regularly the firmware and also NVMe driver from the beginning (v1.1, v1.2,…,v1.5, v1.7 and recently v1.8)
The device is in perfect health:


However, I observed and measured performance is going down each time the NVMe driver version was upgraded !!, and specifically with the last v1.8 recently released.

To be sure of this situation I have run today twice an identical scenario test (under WinRE x64 configuration for practical reason), on the same machine (SabertoothX99), with only changing the Intel NVMe driver version.
Before each test a TRIM optimisation was done with Intel SSD tool.
Here are the figures:
v1.5.0.1002: 100 s
v1.7.0.1002: 104 s
v1.8.0.1011: 137 s

With ANVIL tests, under W10 x64, I observe also a similar downgrade of the scores.

Does any i750 user’s have also observed a such phenomena ?

What sort of scores are that?

@Fernando ,
It is a full sytem backup time executed by the a well know backup tool ‘WinRE’ booted media (USB).
The source is i750 NVMe system.
The destination is 960 PRO 1TB NVMe data device.
The backup image created is 37.5 GB.
Only the i750 driver version varies for each test using the same scenario.
Absolutely none parameters are modified for test 1, 2 and 3.
(a unique occurence of Intel NVMe driver version is selected and then integrated into the WinRE bootable image via NTLite tool, the bootable media is rebuild at each time).