another "which imac?" post

Discussion in 'iMac' started by JMNL, Jun 2, 2011.

  1. JMNL macrumors newbie

    May 11, 2011
    Looking for help on which 27" imac.

    2.7GHz vs 3.1 GHz vs 3.4 GHz

    For now, the heaviest lifting will be some number crunching models that take a few hours to run. These have a simple animation associated with them, but I suspect that the crunching (and my coding) is the bottleneck, rather than the animation. Not currently using Matlab or Mathematica, but have in the past, and may need to do so again in the future. I'm tempted to go with 3.4GHz, regardless of my current needs, because even if a lot of current software doesn't make full use of multiple cores, it seems reasonable to think that future software will. Is that a reasonable assumption?

    512MB vs 1GB vs 2GB video ram

    I don't game. However, the imac will also be my tv (netflix and downloading). How much video memory will that chew? Will 2GB help to futureproof things, or will the graphics processor botttleneck before the memory does?

    Thanks in advance...
  2. dfine1966 macrumors 6502

    Apr 9, 2011
    My father always told me, when it comes to computers, alway gets the best you can afford. Most people will tell you get the better processor, the least amount of memory (since you can add it later for a lot cheaper). I would get the better GPU 2 GB, but 1 GB might be fine. For me personally I would get SSD, since it is difficult to add later.

    I am waiting on my BTO 27 inch, 3.4, 8 GB memory,2GB video card, 256 SSD + 2 TB HDD.

    For you definitely get the high end processor, at least the 1 GB GPU. You will want memory to be at least 8 GB, but you could buy 4 GB and then add from Crucial, another 8 GB for a total of 12 GB for a whole lot less than Apple is charging. Hard drives are up to you and how much money you have to spend.

    Good luck
  3. JMNL, Jun 2, 2011
    Last edited by a moderator: Jun 3, 2011

    JMNL thread starter macrumors newbie

    May 11, 2011
    Thanks for the reply dfine. I generally take the same approach ... but your father likely also taught you about diminishing returns.

    Memory: as you note, and based on the posts I've read here, I think that's better for me to do myself as needed
    SSD: not likely worth it for me – I don't mind if things take a little longer to load initially.

    I've found reading the threads here to be much more useful than looking at benchmarks in reviews. But many of those threads focus on needs for gaming and video-editing, and I've struggled to figure how best to apply them to my own needs. Hence the queries.
  4. Steamrunner macrumors member

    Aug 9, 2008
    Clearly the cost of the 3.4 isn't an issue or you wouldn't be considering it, in which case go for it. That will then give you the 1GB card anyway - which I think will be fine for you. Of course, the extra cost of the 2GB card is relatively small compared to the cost of the 3.4 so it's very tempting to just add it on - and you never know, when it comes time to sell in a few years, that extra 1GB may just make your iMac easier to shift.
  5. blevins321 macrumors 68030

    Dec 24, 2010
    Winnipeg, MB
    Actually video transcoding benchmarks would be a good indicator for math-based algorithm benchmarking :)
  6. bpeeps macrumors 68020


    May 6, 2011
    Post number 3,498 of its kind. Welcome to Mac Forums.

    That said, it sounds like you can afford it OP, so spec it out and be done with it.
  7. Bear, Jun 3, 2011
    Last edited: Jun 3, 2011

    Bear macrumors G3

    Jul 23, 2002
    Sol III - Terra
    Since you have compute intensive Applications:

    3.4 CPU - this can't be upgrade later
    VRAM flip a coin? It sounds like 1GB is all you will need, but it's also something that can't be upgraded later.
    4 GB Ram from Apple

    From what little you've said, odds are more memory will speed things up for you, but like others have said, getting this memory from elsewhere will cost noticeably less.

    And now for the SSD question. It's not only initial load times, it's also if you have a lot of swapping going on. Which you might from number crunching programs. So it sounds like SSD+HD might be a good thing for you. Again, this is based on what little you've said and is more something for you to think about.

    I do agree a few seconds overall time savings is not a big deal, but what if you could could a half hour or more from runs? Would that be worth it to you?
  8. Hellhammer Moderator


    Staff Member

    Dec 10, 2008
    Go with the CPU but save on the VRAM. In most cases, the extra VRAM won't help at all and even if it helped, it wouldn't help much. That 100$ is better spent towards RAM and possibly an SSD later on.
  9. Sirmausalot macrumors 6502a


    Sep 1, 2007
    If your software only takes advantage of one core, the turbo boost on the lower processors will bring it up into the same MHz range as the others. If you have multi core aware applications (or they'll be upgraded in the near future) get the best processor you can.

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