Looking at the single 2.66... Some questions about the future

Discussion in 'Mac Pro' started by fox-orian, Mar 25, 2009.

  1. fox-orian macrumors newbie

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    #1
    I'm an illustrator and concept designer, I do video editing, sound recording, 3D rendering, etc off to the side, so I use all the apps in the adobe master suite and final cut and whatnot. Currently I'm using a 24" iMac [mid-2007 model] and while it's been doing a good job, it's unfortunately just been losing steam as my projects get larger and larger. I think it's about time I move on up to a more powerful system that will last me longer. Luckily a friend of mine is interested to buy my iMac, so the cost of a Mac Pro won't be quite as big of a problem.

    I have my eye on the single 2.66 4-core system, as I think the 8-core becomes a little too expensive for my taste and I'm pretty sure the single 4-core should suit my needs fine. [After I sell the iMac, I can get the Mac Pro for about $1200. Not too bad.]

    My real question though, is about the removable logic-board tray in the new nehalem based pros.

    First up, it seems like this would make upgrading the processor pretty easy in the future if I'd need to. I assume it's possible to upgrade the Mac Pro's Xeon processors with other faster Xeon's? I'd like to say I assume it's possible, anyway.

    Second up, lets say down the road I'd like to have the dual processors. Is it possible to actually interchange the logic-board tray from a single one to a dual one without having to get a whole new system? If so, that's pretty intriguing to possibly be able to get a major boost in perfmance at a cheaper cost than getting a whole new Mac Pro. If not, I assume this has to do with the boards in the system having different architecture to not operate with two processors when it was designed for one. [Or the trays have different connectors or something.]

    Also, one last little question, in the experience of PowerMac/MacPro users around here, what's the expected lifespan of a Mac Pro, would you say? By buying one, I'd like it to last quite a while with the work I do. [I'm looking at the Mac Pro because I'm looking to it as a system that will still be reliable as much as 5 years down the road.]

    Any help on that stuff above would be much appreciated :)
     
  2. GodWhomIsMike macrumors 6502a

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    #2
    My HUGE issue with the single 2.66GHz system is the 8GB limit. I am truely hoping that it can take up to 16GB, but everything up to now is indicating that 8GB is the limit.
     
  3. nanofrog macrumors G4

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    #3
    It can use larger capacity DIMM's, when they become available. Hence the perception of an 8GB limit ATM. Simply parts availability.

    We might see 4GB versions soon, as the manufacturers may be waiting to coincide their release with Intel's Official Release of the Nehalem Server/Workstation parts on March 29. Not too long, to wait and see. ;)
     
  4. phairphan macrumors 6502a

    phairphan

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    We don't know this for a fact. Yes, it's probable they simply listed an 8GB ceiling because of the price/availability of 4GB modules. This wouldn't be the first time that Apple has taken this approach. However, we also have recent examples of platforms known to be capable of higher RAM ceilings unable to address the full amount due to other hardware or EFI choices (a la 6GB practical RAM limit in older MBPs).

    As the owner of quad, I hope the machine is capable of addressing more. Until someone tries it, we don't know. OWC is hoping to have 4GB DIMMs in next week, so check their blog for updates.
     
  5. Sdancott macrumors regular

    Sdancott

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    #5
    Intriguing as this sounds, where would you even buy the (daughter?) boards?

    Sounds like a nice idea, but i can hardly see Apple offering this option
     
  6. phairphan macrumors 6502a

    phairphan

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    The backplane (the board the daughter card plugs into) has the same Apple part number for the quad and octo, so it should simply be a matter of swapping the processor board. I doubt Apple will ever offer this as an option, but in the future you may be able to find deals on partially-broken MPs. As a rule of thumb for the MPs, it's usually cheaper and more advantageous to sell your current machine and buy a new model than it is to try to upgrade your current one (for things like better/faster processors). Xeon prices don't fall much (if at all), unlike Intel's desktop line. A notable exception was the last quad which was simply an octo board sans second processor.

    Of course, Apple has made it so quick and easy to swap out the processor(s) and memory in these new MPs, it would be fairly easy to find a "steal" out there in the wild (runs off to buy a lock for his new MP). :D
     
  7. nanofrog macrumors G4

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    As far as tested, No. But again, the parts aren't yet available, so testing it is currently impossible.

    The architecture Intel designed is certainly capable of doing so. :)

    There's no reason for Apple to disable the use of larger capacity DIMM's though. Perhaps limit the CAS Latency timings to CL = 7, and restrict it to ECC only (block non-ECC varieties, or even Registered), but that's the extent I can think of.
     
  8. huussi macrumors member

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    #8
  9. phairphan macrumors 6502a

    phairphan

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    Yes, the architecture is certainly capable, but the Intel-spec architecture of SR MBPs also supported 8GB and the reality was a bit different.
     
  10. phairphan macrumors 6502a

    phairphan

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    It was probably to stop people from ordering a quad, adding 16GB of memory, and then complaining to Apple when they found out it when have been cheaper to get an Octo + 16GB. Again, if the 8GB ceiling is a deal breaker, then wait for the confirmation.
     
  11. nanofrog macrumors G4

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    #11
    The MP isn't a laptop though. ;)

    I haven't seen an MBP up close, but did it even have the room to squeeze it in (module)? :confused: The DIMM height in the MP wouldn't be the issue, unless it's 10"+. :eek: :p (1TB DIMM's? Not yet anyway). :p
     
  12. phairphan macrumors 6502a

    phairphan

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    It wasn't a height issue. You could fit two 4GB DIMMs, but the system could only effectively address 6GB (some speculation about the memory controller Apple used). The Intel spec for the platform provided for 8GB.

    There shouldn't be a memory controller issue this time, since it's on the processor, but who knows what liberties Apple took with the Intel specification.
     
  13. nanofrog macrumors G4

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    #13
    The controller chip would make sense to me, but that's directly related to my background. Far more than just a firmware limit. Even an OS limit being more of a possibility (if that was the case).

    The MP doesn't have an architectural limit of 8GB though. Not even with Apple's implementation, as the CPU's and chipset is produced by Intel, and no other parts by other vendors that could cause such a restriction. So I keep trying to think of a technical reason for setting such a limit, and I haven't come up with one.

    The only thing that does come to mind, is a means of manipulating more OS X users into the Octo variants. Though it's possible, and we're talking about Apple, I'd think this would hurt more than help.

    So the current DIMM capacity (parts limitation) seems the only valid reason to state 8GB ATM, and I've noticed the specs have been like this before with various user upgradeable items.

    Either way, we'll find out at some point for certain. ;) :D :p
     
  14. phairphan macrumors 6502a

    phairphan

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    That we will. Like I said, I'm the proud owner of new quad so I hope the limit is one based on parts and availability. It would certainly open up the quad to hope a whole group of users who don't need the multiprocessing power of the octo, but can't stomach the 8GB limit for fear of it reducing their expansion options in the future.
     
  15. JimGoshorn macrumors 6502

    JimGoshorn

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  16. fox-orian thread starter macrumors newbie

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    #16
    Aha! That's what I was wondering about. They both have the same part numbers... So in theory it's possible to swap processor boards for a dual processor in the future. I think I would be able to find a processor board in the future for a cheap-ish price [no memory or processors on it, JUST the board] in like 3+ years after owning one for a while.
     
  17. hobes270 macrumors regular

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    #17
    Wow thats sweet, the 2.66 quad can now do 16gb. Is this mean its confirmed?
     
  18. nanofrog macrumors G4

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    #18
    Sorry, I skipped this, in our previous line of posting. ;) :eek:

    The backplane/logic board is in fact the exact same P/N for both the Quad and Octo?

    BTW, out of curiosity, how/where did you stumble on this?

    That would be wonderful news for users! :D

    Last I'd seen, comments didn't indicate the chipset was located on the daughter board. They use different versions; 36S for the Quad, and 36D for the Octo. Various posts lead me to believe the chipset was actually located on the board to prevent users from just getting their hands on the DP daughter board.

    It certainly makes sense from a manufacturing POV, as it's one part for all versions. ;) And what an awesome bonus for potential upgrades. :D
     
  19. phairphan macrumors 6502a

    phairphan

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    #19

    It was in one of the zillion MP threads about two weeks ago. The person posting was obviously an Apple tech or reseller since he/she had parts numbers for every piece of the MP. Of interesting note, the heat sinks on the dual, while appearing identical, have separate part numbers.

    Edit: Here's the thread.
     
  20. phairphan macrumors 6502a

    phairphan

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    Hmmm...it's also worth pointing out the easy to miss "special note." Apparently all of the installed modules in the MP have to be identical 4GB DIMMs. Wonder why?
     
  21. VirtualRain macrumors 603

    VirtualRain

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    #21
    Good question... I wonder if they are Registered ECC?

    The price is not bad... $700 for 12GB is better than the $1600 I saw elsewhere.
     
  22. nanofrog macrumors G4

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    #22
    Thanks for the link. :)

    Some of the detail I was hoping for is missing, but if the P/N's for both the Quad and Octo are the same, then the chipset must be located on the daughter board. SMC is important, but should be stored on a Flash device, and upgradeable, so the same component can be used. Makes sense, as it's different between the SP and DP versions.

    Really good news, for those who might want to upgrade in a year or so. :)
    Perhaps the EEPROM Thermal Sensor (indirectly), as the current would need to be increased. The management would be for the entire memory (simplification for VR's), and not per individual channel or DIMM.
    It doesn't state with any certainty, so it's unknown. :confused:

    As the shipping is pending, perhaps not, and is actually Unbuffered. The thermal sensor makes sense here. (No register, and 2x as many memory chips = higher load). The firmware would sense this, and up the current, so a need for thermal management makes sense.
     
  23. VirtualRain macrumors 603

    VirtualRain

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    #23
    It's possible they used the 36D on the main board for both quad and octo's... to save on parts and motherboard production costs. Perhaps easier to eat a few dollars (us not them) on a chipset than do a different run of main boards. :confused:
     
  24. nanofrog macrumors G4

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    #24
    As I understand Nehalem's datasheets, it's not that simple. A DP processor can run on an SP board, but not the reverse.

    The CPU's don't controll the chipset's QPI lanes. (They can't shut them off/reroute). A DP version does have the ability to shut off thier OWN unused QPI path when used in an SP board.

    So data would be misrouted if you tried to run an SP part in a DP board. Results = crap, if you get any at all. :eek: :p

    Which is why the chipsets are specific. S for SP, and D for DP. (24 & 36 lane flavors, and Apple chose the 36 lane variants).
     
  25. VirtualRain macrumors 603

    VirtualRain

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    #25
    I think it is possible... you could run a SP and a 36D connected to another 36D thus giving you a full 4 x16 PCIe slots... From what I recall from the literature, the QPI are all negotiated/setup at startup and devices all identify themselves, etc. Thus a SP on a 36D chipset should run just fine... The unused link on the 36D will just not initiate.
     

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