Cores and other options for noobs

Discussion in 'Mac Pro' started by Madvillain, Jul 27, 2010.

  1. Madvillain Guest

    Joined:
    Jan 15, 2008
    #1
    Could somebody please post a link to an explanation of all of the different options on the Mac Pros and what they actually mean? I have a ton of questions and would like to read up on things such as the following:

    What exactly does 8-core mean?
    How will 8-core performance compare to 12-core or 6-core performance if both machines have the same amount of ram?
    Why can some Mac Pros hold more ram than others?
    What does 2.66GHz mean, and how does it compare to 2.93GHz?



    Thanks for the help.
     
  2. CaptainChunk macrumors 68020

    CaptainChunk

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    Apr 16, 2008
    Location:
    Phoenix, AZ
    #2
    Oh boy, here it goes....

    1. 8-core refers the computer in question having 8 total physical processing cores. Before multi-core CPUs, a CPU would have one physical processing core on its die (like the Pentium 4 and its predecessors). By having more additional cores, a CPU can perform operations faster through symmetric multiprocessing (SMP), provided the software running can take advantage of it. Currently available 8-core machines from Apple in particular achieve this using two quad-core processors running on the same board.

    2. In software optimized for multi-threading (i.e. software that is multi-core aware), a 12-core machine would be faster than an 8-core machine, which in turn would be faster than a 6-core machine, and so on. From the standpoint of raw CPU performance, the amount of physical RAM makes very little (if any) difference.

    3. 4-core (single-CPU) Mac Pros use a different daughter card than the than 8-/12-core (dual-CPU) Mac Pros do. The way the memory banks are arranged, each CPU present addresses up to 4 memory modules. So on the 4-core, there's 4 and on the 8-/12-core, there are 8. So, in essence, the 8-/12-core machines can handle twice the maximum RAM.

    4. 2.66GHz refers to the clock speed of the CPU. In theory, a 2.93GHz CPU would perform the exact same task more quickly than a 2.66GHz CPU using the same architecture would, though a 264MHz difference (9%) isn't terribly significant, especially given the price differences on Xeon CPUs.
     
  3. Matthew Yohe macrumors 68020

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    Oct 12, 2006
    #3
    8 Processing cores on a single chip. The whole cpu industry transitioned into running processors in parallel rather than just increasing a single core's ghz. (Partially because it's getting harder to make the processors much smaller)

    It's the difference between this:

    [​IMG]

    and this:

    [​IMG]

    Greatly depends on what applications you're running through it. Also depends on the type of processor used. If you look there are options for the old Nehalem model processor and the new Westmere. You'd have to look at processor benchmarks to find out which processor at which speed would be "better."

    Either limitations imposed by the hardware, or by Apple. Apple may not certify some of the models they sell to run 32GB but they still can. It's not the "recommended" manner to run however.

    Again this differs between the kind of processor. How many cores it has etc. If it has 8 cores at X GHz and 6 cores at Y GHz, that is certainly different.

    Basically, if you don't really know this stuff, any more explanation than this isn't going to help much. You should probably just describe the software you want to use, or how you really want to use a new mac. I would imagine you wouldn't even need a Mac Pro.
     
  4. alust2013 macrumors 601

    alust2013

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    #4
    If you've got basic questions, chances are, you don't need something as powerful as a Mac Pro. If you feel you do, you may want to talk to someone at an apple store to see what might be the best fit for you. Also keep in mind, they will likely try to upsell you a bit, so perhaps take a step down from what they recommend, if money is an object.
     
  5. TheStrudel macrumors 65816

    TheStrudel

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    Jan 5, 2008
    #5
    It means you probably shouldn't be buying a Mac Pro.

    No, seriously. If you have to ask what all this means, you can definitely get by with a much slower, much cheaper machine.

    CaptainChunk's answers are correct.

    Some things to keep in mind:

    Very little software can actually use all of this, and most software is still 32-bit, and cannot address more than 4 GB of RAM. This is only now starting to change, except for video compression, which has been able to max out cores.
     
  6. CaptainChunk macrumors 68020

    CaptainChunk

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    #6
    (to the OP) Also, it's important to evaluate what you'll actually be using the computer for, especially considering you're asking these questions to begin with.

    If it's just for every day computing, like surfing the web, checking email and playing a few games, buying a Mac Pro is almost completely insane. They're very expensive machines to begin with and only get more expensive as you add options.

    For the majority of Mac users, a Mini or iMac would suit their needs amply. For example, you can get a fast iMac with a quad-core processor and 27" screen for considerably less money than a similarly equipped quad-core Mac Pro, if you don't need the internal expansion (and believe it or not, most people really don't).
     
  7. Madvillain thread starter Guest

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    Jan 15, 2008
    #7
    Thanks for all the replies.
    I appreciate the comments about probably not needing a pro if I have to ask the questions I did. I understand that logic.

    My main use for the computer would be for photography - editing dng files in Photoshop cs5. I currently use a late 2008 MacBook (2.4 ghz with 4gb ram) and the 24-inch apple cinema display. I have to use external drives to store and backup my photos as they won't fit on my drive. I do what I would consider to be processor heavy stuff, but I am clearly out of my league here and may not actually be doing what you guys consider heavy work. The stuff I do includes merging multiple images into hdr photos, panoramic photos, and creating multiple layered tif files. I also use a wacom tablet to 'paint' photos which often really slows things down. I thought a Mac Pro would be the way to go as I could have a scratch disk for cs5 and be able to swap out the hard drives as they filled up in addition to having the processing power to not have to wait around while a tif file was being imported from CS5 to LR3.

    Thoughts? Am I nuts considering a Pro?
     
  8. alust2013 macrumors 601

    alust2013

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    #8
    Actually a Pro would likely benefit you with that kind of stuff, although you could get away with spending a lot less money with, say an i5 iMac. What you are doing may be a bit heavier than the MacBook would like to handle, but the iMac would be able to do that much more easily. I'm not an expert with photography, so I could be slightly off base on that, but I'd say that could do what you need it to. However, if you do go with the pro, a quad-core should do you fine.
     
  9. CaptainChunk macrumors 68020

    CaptainChunk

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    #9
    Not necessarily. You already have a 24" ACD, so if you think having internal expansion for hard drives and the like would help your productivity, I'd look into something like a quad-core or (perhaps) a six-core Mac Pro. A lot of my photographer friends use quad-cores. While CPU speed does count somewhat, I'm sort of doubting having a 8- or 12-core machine will benefit a still photographer much, especially in Photoshop (which won't utilize anything beyond two cores anyway).

    In other words, you'd probably benefit more from the upcoming 2.8GHz quad than you would with say, the 2.4GHz 8-core (both of which launch next month). Faster clock cycles will likely matter you to you more than having additional cores you won't use. Disk speed and RAM will matter you the most.

    A quad-core 2.8 with 8GB of RAM would probably be a decent place to start. But buy your RAM upgrades elsewhere. Apple charges too much. ;)
     
  10. Madvillain thread starter Guest

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    Jan 15, 2008
    #10
    Can you get the same RAM from OWC as you can from Apple?
    Can you mismatch the amount of RAM in each slot (ie - 2gb, 2gb, 2gb, 4gb)?

    Do you know much about the scratch disk in Photoshop? I was considering getting a SSD in one of the drive bays and using it for running my system and also as a scratch disk. Can both be done, and if so, would it be beneficial?


    Thanks again for the help.
     
  11. eponym macrumors 6502

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    Jul 2, 2010
    #11
    You can definitely get the RAM you need from OWC. You can get it most anywhere that sells computer components. Apple doesn't make the RAM that's in their machines. And yes you can mismatch (as far as I know). There's a tiny performance degradation from not using pairs, but it's only something like 3 or 4% (iirc).

    Definitely do NOT use a SSD for your scratch disk. The scratch disk is simply a temporary place for Photoshop to store data while you're working.

    When you quit Photoshop or restart the machine, that data goes bye-bye.

    SSDs degrade in performance from constantly writing and re-writing data—which is exactly what a PS scratch disk would be doing.

    Use a normal hard drive and get lots of RAM (but feel free to use a SSD for your startup disk...).
     
  12. CaptainChunk macrumors 68020

    CaptainChunk

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    #12
    1. While it might not always come from the exact same supplier, OWC sells RAM guaranteed to work with your Mac and comes with a lifetime warranty. Not much to worry about there.

    2. On the quad-core, you can do mismatched RAM configurations, although you will get the better performance with either a dual channel or triple-channel configuration (matched pairs or matched threes). If for example, you went with 8GB of RAM, you'd install 4 2GB modules and populate all the slots. OWC also has a program where they'll buy back your unused modules, so if you get the stock 3GB configuration from Apple and buy an 8GB upgrade kit from them, they'll buy the three stock 1GB modules from you.

    3. If you're going to run a scratch disk for Photoshop, you'll want to keep it on a disk that's physically separate from your boot. Never use your boot disk as a scratch disk. It kills performance. What I would look into is perhaps using a small (like 80GB or so) SSD for boot, OS and applications. Then, use a larger mechanical drive (like 1-2TB) for scratch and storing other data like music and movies (if that's your thing).
     
  13. TheStrudel macrumors 65816

    TheStrudel

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    Jan 5, 2008
    #13
    You definitely will not want a more expensive Mac Pro. The expandability is a good reason to buy one - the achilles heel of the iMac, though two internal drives makes it a lot better than it was.

    You won't need more than four cores; the increased core count is more for the video crowd. You can also probably get by with ~8 GB of RAM, given your workload, which is quite affordable from OWC.
     
  14. Madvillain thread starter Guest

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    Jan 15, 2008
    #14
    Okay. So it looks as though I would be best to go with the 4-core 2.8 Ghz.

    8gb sounds like a good start, and it also matches the greatest speed bump on the adobe benchmarks. It looks as though going over 16gb really doesn't do much at all (meaning the 8-core is not worth it for me, as was pointed out).

    So...
    Perhaps a 2.8 quad core with 2 x 4gb so I would be able to jump to 12 or 16 easier.
    A 120 GB SSD drive for the OS and applications.
    Two 2TB drives for my photos and other media.
    And a small drive for a scratch pad for CS5.

    Thoughts?
    I'm still a bit confused about the scratch pad. I've read up on it but still don't seem to grasp what it does.

    Thanks again for all the help.
     
  15. Madvillain thread starter Guest

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    Jan 15, 2008
    #15
    Forgot to add...


    Graphics. What is the consensus there? Does CS5 hand off the generation of the image to a graphics card, or how does that work? Is the graphics card more for gaming frame rates?
    Thanks for the education so far.
     
  16. TheStrudel macrumors 65816

    TheStrudel

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    #16
    All of the GPGPU work is minimal so far, so unless you have a very specific need, you'll see very little benefit. Photoshop can't fully use even the base GPU's hardware. I might also add that the base GPU option is by far and away the most powerful base GPU option  has ever shipped.

    Motion can use the graphics card more than any other pro apps, and even then it isn't that much. I expect  to leverage OpenCL to really push GPUs in the next version of Final Cut Studio, but we don't know when that will be.

    You don't use it anyway, so you can safely ignore GPUs unless you want to do a lot of gaming.
     
  17. Hamsterz macrumors member

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    Sep 22, 2008
    #17
    I am a web designer (and starting a game designing branch) and I spend a lot of my time in Photoshop. I used a mid ranged late 2006 macbook (2.0 ghz, 1 gig of ram) at first, and it was too slow for my needs (I had to visit a mac pro once a week to get any work done). I now use a MBP (late 2006, 2 gb and 2.33 ghz) with CS3, and its plenty fast for now.


    Next time I upgrade, I will most likely be getting a higher end Mac Pro (thats saying I make enough money off of new projects being started with web designing)

    I suggest the mac pro, honestly. Although you had newbie questions, you use your macs. (the people like me who know all about hardware don't get as much work done.. -cough didnt say nothing-)

    EDIT: Also, I suggest 100% multi displays. You can have photoshop in one window, and a movie to make it so you're not bored, skype, and your email in the other.

    I'd also suggest getting the 5790, since I expect it to be a 149.99 or somethin difference, and its a big step up. Although, right now, you may not be using it, a Mac Pro could last you 5 years and Photoshop Cs7 or whatever they have then could use the graphics card and all the cores (by then, we'll be all using 128 bit computers, have 200 gigs of ram and 20 core processors..)
     
  18. Madvillain thread starter Guest

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    #18
    What is a 100% multi display? Do you mean multiple displays (what's the 100%)?

    I currently use a 24-inch ACD with my MacBook and will get another display when I get a Mac Pro so that I've got dual displays again. I really like the dual display with Lightroom and Photoshop. It's great.
     
  19. chrono1081 macrumors 604

    chrono1081

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    #19
    The system you had picked out a few replies up would be perfect. 8 gigs should be a good amount to start with.

    I use Aperture a lot and rarely use up my 8 gigs anymore (unless I open one of my memory hogs like Maya or Unity :p )
     

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