The TDK packages on the back are external magnetics for the ethernet ports. Ethernet is balanced, which means you can hook a pair up to one coil of a transformer and the other coil will spit out the same signal, but with DC isolation.
The two enclosed sections at the bottom of the back of the board are clearly something RF-related. One for 2.4 GHz, one for 5 GHz. At a guess, I would say maybe a set of RC filter networks for the receive chains.
It is physically replaceable, but my understanding is this can only be done by an authorized service provider. Not yet sure if that is a technical limitation. I would love to see more detail on this.
Does it accept exactly the same flash boards as the iMac Pro, or are these a new version?
What happens if you take a unit with the default 256 GB drive (as we see above, comprised of one board) and add another 256 GB board?
What if you take a unit with two boards and remove one board? At a minimum, it would require reformatting, since half the data would be gone, but does it work after formatting?
Can you run two boards of different capacities (256 GB and 512 GB, for example)? This can probably only be answered after the question about adding a second board to a unit which shipped with only one.
It’s worth noting for anybody unaware: this is not exactly an SSD. It’s a card with flash chips and a buffer, but no controller. The controller is the T2, which is on the logic board.
This makes aftermarket storage easier to manufacture (no need to source a controller or the firmware for it), but due to the limited market, I wouldn’t expect to see anybody but Apple make these modules.
@grantspedding The T2 does not prevent an external computer from reading the SSD. It is connected to one of the USB-C ports. There is a tool you can connect which will boot the T2 in DFU mode, prompt for the user’s password, tell the T2 to load the SSD, then dump all the data to an external drive.
Though I seriously wonder what professional would use a machine with no backups of in-flight work. Especially when it’s a Mac, and every macOS since 10.5 in 2007 has included Time Machine.
The speaker enclosures are mostly to eat the sound which would otherwise radiate from the back of the driver. A free-floating electromagnetic speaker radiates from both sides of the membrane, but 180º out of phase, and the resulting audio interferes with itself in complicated ways. By having one face radiate into an enclosure, you get less self-interference. The problem is enclosures contain air, radiating sound into them compresses that air, and air doesn’t want to be compressed. A larger enclosure presents less resistance to the driver’s movement. Odd shapes don’t help quite as much as regular shapes, but the added volume is still beneficial.
@repoman27 @Walter Five flash chips is a little odd, but flash chips are made in odd sizes. The 2018 Retina MacBook Air had three flash chips at 43 GB each for a total of 129 GB, sold as 128. This was also the reason for its weird 1.5 TB max capacity. The 2019 refresh dropped to two chips.
My bet is 103 GB flash chips are a little bit cheaper per gigabyte than 128 GB. 1 TB and up will probably be eight chips.