@george1421 Thanks for the reply.
Basically there is no other errors and the original issue is present again, slowness like the disk is back in low power mode.
I have done some investigations to find the difference between the two G6s and have re-imaged a working one fine and failed on the newer G6s. The difference appears to be with regards to SSDs.
Working G6s have West Digital and non-working have Samsung.
I can confirmed this on 10 of each and it appears the nvme_core.default_ps_max_latency_us=5500 command has no effect on the Samsung SSDs.
Here is a putty extra of a non working G6 with a Samsung SSD.
00:00.0 Host bridge [0600]: Intel Corporation Device [8086:3e34] (rev 0c)
Subsystem: Hewlett-Packard Company Device [103c:854a]
lspci: Unable to load libkmod resources: error -12
00:02.0 VGA compatible controller [0300]: Intel Corporation Device [8086:3ea0] ( rev 02)
Subsystem: Hewlett-Packard Company Device [103c:854a]
00:04.0 Signal processing controller [1180]: Intel Corporation Skylake Processor Thermal Subsystem [8086:1903] (rev 0c)
Subsystem: Hewlett-Packard Company Device [103c:854a]
00:12.0 Signal processing controller [1180]: Intel Corporation Device [8086:9df9 ] (rev 11)
Subsystem: Hewlett-Packard Company Device [103c:854a]
00:14.0 USB controller [0c03]: Intel Corporation Device [8086:9ded] (rev 11)
Subsystem: Hewlett-Packard Company Device [103c:854a]
Kernel driver in use: xhci_hcd
00:14.2 RAM memory [0500]: Intel Corporation Device [8086:9def] (rev 11)
Subsystem: Hewlett-Packard Company Device [103c:854a]
00:15.0 Serial bus controller [0c80]: Intel Corporation Device [8086:9de8] (rev 11)
Subsystem: Hewlett-Packard Company Device [103c:854a]
00:15.1 Serial bus controller [0c80]: Intel Corporation Device [8086:9de9] (rev 11)
Subsystem: Hewlett-Packard Company Device [103c:854a]
00:16.0 Communication controller [0780]: Intel Corporation Device [8086:9de0] (r ev 11)
Subsystem: Hewlett-Packard Company Device [103c:854a]
00:1c.0 PCI bridge [0604]: Intel Corporation Device [8086:9dbc] (rev f1)
Kernel driver in use: pcieport
00:1c.7 PCI bridge [0604]: Intel Corporation Device [8086:9dbf] (rev f1)
Kernel driver in use: pcieport
00:1d.0 PCI bridge [0604]: Intel Corporation Device [8086:9db4] (rev f1)
Kernel driver in use: pcieport
00:1f.0 ISA bridge [0601]: Intel Corporation Device [8086:9d84] (rev 11)
Subsystem: Hewlett-Packard Company Device [103c:854a]
00:1f.3 Multimedia audio controller [0401]: Intel Corporation Device [8086:9dc8] (rev 11)
Subsystem: Hewlett-Packard Company Device [103c:854a]
00:1f.4 SMBus [0c05]: Intel Corporation Device [8086:9da3] (rev 11)
Subsystem: Hewlett-Packard Company Device [103c:854a]
Kernel driver in use: i801_smbus
00:1f.5 Serial bus controller [0c80]: Intel Corporation Device [8086:9da4] (rev 11)
Subsystem: Hewlett-Packard Company Device [103c:854a]
00:1f.6 Ethernet controller [0200]: Intel Corporation Ethernet Connection (6) I2 19-V [8086:15be] (rev 11)
Subsystem: Hewlett-Packard Company Device [103c:854a]
Kernel driver in use: e1000e
01:00.0 PCI bridge [0604]: Intel Corporation Device [8086:15e7] (rev 06)
Kernel driver in use: pcieport
02:00.0 PCI bridge [0604]: Intel Corporation Device [8086:15e7] (rev 06)
Kernel driver in use: pcieport
02:01.0 PCI bridge [0604]: Intel Corporation Device [8086:15e7] (rev 06)
Kernel driver in use: pcieport
02:02.0 PCI bridge [0604]: Intel Corporation Device [8086:15e7] (rev 06)
Kernel driver in use: pcieport
03:00.0 System peripheral [0880]: Intel Corporation Device [8086:15e8] (rev 06)
Subsystem: Hewlett-Packard Company Device [103c:854a]
39:00.0 USB controller [0c03]: Intel Corporation Device [8086:15e9] (rev 06)
Subsystem: Hewlett-Packard Company Device [103c:854a]
Kernel driver in use: xhci_hcd
3a:00.0 Network controller [0280]: Intel Corporation Device [8086:2723] (rev 1a)
Subsystem: Intel Corporation Device [8086:0084]
3b:00.0 Non-Volatile memory controller [0108]: Samsung Electronics Co Ltd Device [144d:a808]
Subsystem: Samsung Electronics Co Ltd Device [144d:a801]
Kernel driver in use: nvme
Steven