Hello OrgamiFan1–
Thank you for the reply.
However, as you have observed: Apple’s Technical Specifications for the Mac Pro 🖥️ (2023) posted on the Apple 🍎 website for the Mac Pro (2023) is woefully inadequate and really says nothing.
Just like MPEG-4 is a family of standards and not just a single CODEC (it can be a basic MP4 or MPEG-4 Part 10 (H.264) aka AVC (or AVCHD) and anything in between),
similarly Serial ATA is not just 1 set standard: in addition to generations SATA I, SATA II, SATA 6 Gb/s,
each generation and revision has optional features such as
- NCQ (Native Command Queuing), hot plug/unplug support
- Staggered spin up (to prevent overloading the power supply)
- Spread spectrum clocking (to reduce the impact of any electromagnetic interference on other devices)
- eSATA (external Serial ATA) which requires a slightly higher voltage to allow for longer external cable lengths
- eSATAp (power [over] eSATA) which combines eSATA with a co-located USB port to provide power to the eSATAp compliant device
and of course
- Port Multiplier support and if it supports port multipliers, which kind:
- the inferior kind (Command Based switching):

or the much better
- FIS (Frame Information Structure) based switching which allows simultaneous access to all the drives connected to the port multiplier:

(and requires NCQ to also be implemented for it to work)
In the Microsoft Windows 🪟 ecosystem, each computer 🖥️ or motherboard manufacturer clearly specifies which manufacturer and model storage (or other onboard device) controller they provide (e.g. the ASUS Pro WS WRX80E-SAGE SE motherboard with the AMD WRX80 chipset for AMD Ryzen Threadripper Pro processors provides 4 additional Serial ATA 6 Gb/s ports via the ASMedia ASM1061 Serial ATA 6 Gb/s controller internally on board in addition to the 4 provided by the AMD Ryzen Threadripper Pro System on Chip (since it is based on the AMD Epyc server processor which directly provides a SATA controller onboard the processor as a SoC) or AMD WRX80.
So all I would have to do is go to the webpage for ASMedia ASM1061 Serial ATA 6 Gb/s controller (or contact) and get all technical specifications that ASUS does not explicitly list and contact ASUS technical support to find out if any of the features listed by ASMedia for that controller have been disabled by ASUS as the OEM (as an aside: ASMedia is a subsidiary integrated circuit design company and division owned by and within ASUS that also sells its controllers and bridges to 3rd party OEMs such as Apple 🍎).
Every Apple sales advisor, Genius at the Apple 🍎 Store or Senior Advisor at AppleCare technical support draws a blank when I ask them the same thing that lowest level rep at ASUS, MSI, Gigabyte, HP, Dell, or SuperMicro is able to answer without any struggle that Apple 🍎 clearly demonstrates.
The fact that I am unable get an an answer to this basic level pre-sales question from anyone at Apple 🍎 is disappointing, bewildering, and unacceptable. I hope Apple 🍎 improves providing this information to customers.
As far as the Mac Pro 🖥️ (2023), the specific Serial ATA 6 Gb/s controller to drive the onboard SATA ports can easily be identified be looking at label 🏷️ on the integrated circuit (chip) presumably located on the underside of the logic board:

(screenshot of the YouTube video of the Mac Pro 🖥️ (2023) teardown by iFixIt, but the resolution is too low and blurry to identify anything other than the big silver colored Microchip Technology PCI-Express switch).
System Information identified the manufacturer as ASMedia SATA 6 Gb/s controller as previously mentioned, just not which specific one:

If anyone can look at it and identify it and tell me: that will go a long way to getting this question answered.
[Edited by Moderator]