I piled through the firmware/rubble from the new iMac Pro – to be released in December – and it appears to be coming with a Security Enclave Processor (SEP). You know. Like the one that was added to the MacBook Pro’s with Touch Bar and Touch ID, but this time to (also?) support a new feature called Apple SecureBoot (for the SEP only?). Here are some of the properties that it uses:
AppleSecureBootPolicy
ApECID
ApChipID
ApBoardID
ApSecurityDomain
ApProductionStatus
ApSecurityMode
Edit: ApSecurityMode appears to support a customer and developer mode.
The iMac Pro may eventually support – with a later firmware/seed update – a Magic Keyboard with Touch Bar and Touch ID – perhaps optionally – but I’m not saying Apple will. That is still a mystery. The fact that Device (ASOC) is missing in the currently available ACPI tables may hint to not.
And in case you have missing it, the iMac Pro comes with the AMD Radeon Vega 10 Video Adapter. Ok. You knew that already, but there are a ton of new device properties. Some starting with ATY,Japura. The AMD10000Controller.kext also includes references to ATY,Iriri and ATY,Kamarang and the IOPCIMatch is set to:
0x68601002, 0x68671002 and 0x687F1002 (Vega RX).
Edit: Oh wow. This is news. The iMac Pro comes with one of the Intel Purley Xeons with a LGA3647 socket? Not a LGA2066 socket?
Edit-2: I am sailing – you know on a boat – and Internet access is not great. Had no access. Not for hours. Anyway. I did find a lot of source code paths with Basin Falls in the firmware. Like for example:
Vendor/Intel/IntelBfs/BasinFallsSiliconPkg/Me/MePlatformReset/DEBUG/AutoGen.c
Vendor/Intel/IntelBfs/PurleyPlatPkg/PlatformDxe/PlatformType/PlatformType/DEBUG/AutoGen.c
Edit-3: The information on the Intel roadmap for Basin Falls, aka workstations with a single processor, points to a “Server Socket R” (the R4 socket). The top of the line Xeon’s (Platinum and Gold) use a LGA3647 (Server Socket P) and supports six memory channels. The images of the open iMac Pro on Apple’s website show “only” four memory modules. As noted by a reader in the comments.
The filenames use both “Basin Falls” and “Purley” in them and thus suggest that Apple is in fact using Purley Xeon’s, but I don’t expect Apple to use Platinum or Gold Xeon’s. The latter are destined for scalable server grade hardware with 2, 4 or 8+ processors. In short. The iMac Pro may come with a Purley Xeon, but not one with a LGA3647 socket.
Edit-4: Ok. The iMac Pro will likely get Xeon SKU’s of the following Intel Core-X models:
Intel 7980XE (18 cores/36 threads/42MB Cache/Turbo Boost TBD)
Intel 7900X (10 cores/20 threads/23MB Cache/Turbo Boost 3.0 Max 4.5GHz)
Intel 7820X ( 8 cores/16 threads/19MB Cache/Turbo Boost 3.0 Max 4.5GHz)
LGA 2066 socket R4 with four memory channels. That’s it I guess.
Pike's Universum 
Edit: Oh wow. This is news. The iMac Pro comes with one of the Intel Purley Xeons with a LGA3647 socket? Not a LGA2066 socket?
Man I don’t know have you seen the coolers on those things? I think they HAVE to be watercooled! These things are going to run super hot!
Well. Intel also has three Purley Xeons with an M at the end 😉
Note: Hacking the firmware is far from exact science. Nobody but Apple and Intel knows what Apple is going to use, but the file/path names in the firmware suggest that this is what Apple is going to use.
Hi Pikeralpha,
The LGA3647 Socket is currently used for Xeon Phi KNL and is announced to be used for the Xeon Skylake. One of the main difference of this socket with other ones, including the 2066 one, is that it works with 6-memory channel whereas pictures on the iMac Pro page from Apple show only 4 RAM DIMMS. Do you really think that it would make sense for Apple to use such a socket?
Yes. I am aware of it. Good catch. I had seen that as well. This is something that is bothering me, but looking at all the path/filenames with purley in it. I’m puzzled.
More importantly. Let’s not forget that I extract data from the currently available firmware package, and thus anything is possible. It’s still inconclusive. We don’t even know if this firmware is used or will ever be used by Apple (hardware). We know that it will be Xeon processors, and the firmware refers to Skylake, but next to that…
Next to that. Most of the information is still under NDA wrap, and not much is freely available.
According to Intel documents ( http://www.cpu-world.com/news_2015/images/L_Purley_platform_comparison.jpg ) Purley platforms run on socket P which is another name for LGA3647.
In the end, I would bet for a Core i9 with ECC support rebranded as Xeon (the same way enthusiast Core i7 and Xeon E3-16xx are almost the same) on an 2066 socket for the iMac Pro, and Apple working on a real Dual-Socket Xeon (Purley platform) for their next Mac Pro. This would make more sens.
I already edited my blog article (see Edit-3) and mentioned the to be used socket options, and the Core i9 With ECC support may also share Purley in its name. We don’t know, but why else would that name be used, by Intel, in the filenames?