Unused Bits in Processor Model Check…

I blogged about checks for two unused processor models when Sierra DP-4 was released and there are still a couple of unused bits – in High Sierra as well – that Apple could use for two Coffee Lake processors and the new Mac Pro. Here’s the data:

bit-10 (0x0400) possibly reserved for Coffee Lake Mobile
bit-11 (0x0800) possibly reserved for Coffee Lake DT
bit-15 (0x8000) possibly reserved for Scalable Xeon

Currently there is no processor model check that selects 0x400, 0x800 or 0x8000 in _xcpm_bootstrap, but they are checked in two other routines. Being _xcpm_init_complete and _xcpm_monitor_init. The bits corresponding to 0x400, 0x800 and 0x8000 are also set in most of the programmed MSR’s (Model Specific Registers).

We know what Apple did in the past for Skylake and Kaby Lake processors, and this combined with the two new Coffee Lake CPUID’s, that makes it the third piece of evidence pointing to refreshed hardware.

Please note that Apple may choose to update certain Mac models, silently. Like they do more often. Or at a later date, but I don’t believe that Apple will skip Coffee Lake processors altogether. To me it’s the most obvious processor for the next MacBook Pro, iMac and Mac mini.

That leaves us with bit-15 (0x8000). This value can also only be used for an Intel processor with a CPUID that isn’t already supported by the XNU kernel. And since there is only one bit reserved, this could mean that it won’t be used for a combination of desktop and mobile processors. Like Skylake, Kaby Lake and Coffee Lake processors.

It is also highly unlikely that it will be used for another processor in the Xeon W serie. Leaving one processor serie that isn’t used yet. And in case you didn’t know this already. I found references to the Intel® Xeon® Scalable Processors in the leaked firmware for the iMac Pro. This processor serie uses the FCLGA3647 socket, and could be used in the new Mac Pro. That is. If Intel isn’t releasing yet another new Xeon processor serie. Anyway. For now. Two possible candidates for the new Mac Pro are:

– dual Intel® Xeon® Gold 6144 Processor (3.5GHz/4.2GHz Max Turbo, with 16 cores and 32 threads.
– dual Intel® Xeon® Gold 6146 Processor (3.2GHz/4.5GHz Max Turbo) with 24 cores and 48 threads.

Note that I used these two, specifically, because of its high base frequency and maximum turbo frequency. Next to that. There is still a thread limit. Even in High Sierra, so either that has to change – which is pretty easy for Apple to fix – or the next Mac Pro won’t support more than 24 cores (and 48 threads).

The only problem that I see right now is that the processors cost an arm and a leg, and that would limit it to a much smaller group. The so called ‘pro-users’. Or people with deep pockets. For the rest of us. Ordinary people. It’s just too expensive.

But hold on. The iMac Pro might be too expensive for some of us, but it will also be good enough for the majority of pro users, and that is probably also the main reason why we are still waiting for a new Mac Pro. I think that Apple isn’t buying the complaints of the small pro-user group.

Historically we had two possible desktop Macs that could fit the need for pro-users:

1.) Mac mini
2.) Mac Pro

But that could change to this:

1.) Mac mini
2.) iMac Pro
2.) Mac Pro

But without a new Mac mini and Mac Pro update, we’re pretty much toast…

What do you think?

13 thoughts on “Unused Bits in Processor Model Check…

  1. I think the Mac Pro and iMac Pro are high up there in the clouds and the gap between Mac mini and them is too big, I think having something like a budget Mac Pro or a Mac mini pro would be a good idea.

    • I’m running a hack with a six core Coffee Lake processor for the last couple of week and I’m impressed by it. Coffee Lake processors could also be used for the new Mac mini. It would certainly close the gap by a large enough margin to make it a powerful and affordable mini Mac Pro.

  2. thread limit now seems to be set @64 and I have tests before with a dual rig with two 2696 v4 xeon with Sierra 10.12.4
    I would like to see unlocked it to 88 cores/thread and would be enough for now because this cpu are affordable without a depth in pocket
    Also for temperatures and power wattage new skyline platinum xeon are to be avoided in my opinion
    Also I would like a new memory limit , in my old experiences 256 gb was not possible.
    ei but if “640 kB ought to be enough for anybody”…

    • Do you see all cores with ioreg?

      The only thing that you can do now is to patch the limit yourself. I think we’ve talked about this in one of the many Github issue. Either you or someone else.

      • Hi,

        Ok so ioreg is indeed limited to 48 logical CPU’s. Thank you for this confirmation.

        Should be patchable, but it sucks to have to patch so many files in order to get every core recognised.

  3. No , maybe with Balamut which have today same motherboard and cpu
    Now I have not anymore dual config rig but when I have had only method to boot was to limit cores via bios to 16 cores for each cpu so in total was 16 cores x2 + 16 threads x2 =64/cores/threads
    Patching kernel was a no go from 63 to 87

    • Hi fabio,

      Yes. You are correct. I checked my notes and the limit is indeed 0x3f/64. And to complicate matters even more, some kexts like AppleACPIPlatform.kext also need the patch. Anyone trying to remove the core limit will have to work his way up from there. I would use a VM for it and see where it panics.

      • Hi Pike
        It would be a great finding for many people over here
        In my test i have tried also to lower that limit in the past to see results but Always panic changeng 0x3f to Others values
        It would also be useful a second option for people who have a dual boot with Windows or other OS
        Now to have a working osx we have to limit cores via bios to 16 for each cpu to reach the limit of 64
        So also Windows starts with less core
        It would be useful to have a patch which allows to limit cores inside bootloader or patching dsdt
        boot-arg cpus=xx not do the job for us
        I hope you have some time to dedicate to this task

        have a nice day!

      • Morning fabio,

        Yeah I guess so, but the thing is. I’m easily distracted. Especially when people don’t push me. When I don’t need it.

        I can ask Asus for a Sage board and I would probable have one here by next week or so, but Intel is not going to give me two expensive processors that ultimately will harm one of their customers.

        Also. I seem to have signed for two other processors, but I never received them, and cannot return them, and thus now I need to pay for them. Probably some criminal here signed for it, and of course without giving me the hardware. Which sucks. This has happened a few times now and Intel isn’t buying it anymore. Deliveries here are the worse I have ever seen.

        And you know what. I am sitting in a hotel room right now, in the Netherlands, just to get hold on my iPhone X, because I know that otherwise it would have been lost somewhere between the airport and our home. Complete madness.

        Another thing is that I need to buy new hardware after my retirement @ Google Inc. and my income will be nowhere close to what I earn right now. Meaning that I don’t know what the future will bring for us and I am going to take things more seriously. I have to take a step or two down probably.

      • Hi Pike your thoughs are right and you have to follow your interest as you always have done
        For me Hackintoshing is a fun and I have learned many things from you and other “guru” addicted and I find it useful I can test thing with my hardware as always do (limits is my knowledge)
        If I was Apple, Intel, Nvidia or AMD..I will send to you all you need because in many case they can use your work to have better product and performances…Real life is different!
        So we trust in you! :-))))
        I am joking
        forgive me and do as always what you want and what is the best for you and family 😉

        Here iPhone X will cost 200€ more than in other part…but this not stop me to buy one on January! 🙂

  4. Pike, I feel your pain with deliveries. Even thought I’m in US package thief’s are headache. I’ve setup a cameras outside with motion sensors to alert me when someone is at the door, might work for you too.

    In regards of patching files, I’ve tried with my little knowledge, wasted 2 weeks debuging kext files and the kernel with no luck at all on my part.
    Seems like somehow the deeper I dig the deeper I sink.

    I am planing on getting the Sage from Asus and the rest of the hardware after new year in January. My biggest pickle is in the hardware support on the cores and memory limits. Feels like buying Shelby for the badge and driving in the parking lot.

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