I noticed what appeared to be an SSD firmware update in one of the packages I looked at.
I don't know if we've accounted for the fact that the Apple SSD itself is special.
While NVME is a standard, Apple has little reason not to add something special to the mix.
Especially if it is to account for potential problems in shipped hardware on early platforms.
I haven't looked carefully into the reported success/failures of the late-2015 SSD upgrades by
board ID, etc.
Are the different board IDs distributed equally among different configurations?
Could the HDD-only boards have some hardware issue where they can't handle SSDs?
It is possible the HDD-only boards have components which can only handle so much I/o?
I also noticed that the 3rd party SSDs by Fledging which are resold by hatssd on eBay
have a Read/Write limit of 2800MB/1600MB per sec, which is still far higher than the Apple
OEM SSD parts, but lower than the 3rd-party SSDs that we are typically installing.
Is that a hardware limit or something capped in the firmware to account for problems like this?
I haven't asked them.
I've been booting of a SATA disk in the meanwhile. My iMac functions well enough with that
so I've punted on the SSD upgrade for now. The 970 EVO which I put in my late-2015 iMac
has panic issues associated with the NVME driver with sleep and otherwise.
We should know more when MBehr2 tries the official apple SSDs and compares them with 3rd-party ones if he has a machine that was originally HDD or 24GB fusion drive only.
[doublepost=1553730589][/doublepost]From the package, it appears the latest OS release rolls in all the previous firmware updates for all aspects of the system, though I haven't verified that empirically. The manifest has checks for all the boardIDs and appears to have a payload for all other firmware in the system.