21.5" - Do I need an i7/16GB ram ?

Discussion in 'iMac' started by jawn12, Jan 8, 2013.

  1. jawn12, Jan 8, 2013
    Last edited: Jan 8, 2013

    macrumors newbie

    Sep 25, 2012
    Hi guys. I'd like to buy the GT 650m/Fusion Drive 21.5" iMac (27" is not an option) although I'm unsure whether or not to jump on the 16GB ram and i7 CPU options. I want something that will last me for at least 3 years with good resell value, and I'll primarily be using it for multiple-tabbed browsing (incl. YouTube), word processing, Skype-ing, iTunes, light movie editing and moderate gaming (Guild Wars 2, Diablo III, etc)--possibly all at the same time, even. :p

    When it comes to ram, I did some tests on my current computer with a bunch of applications open and found that I was generally using up around 3 or 4GB, though that would fluctuate if tabbing more/gaming. Thus, I understand it, the 8GB option would suffice here, however will I be future proof? I know the ram from Apple is expensive, but since it's not user-upgradeable on the 21.5", I don't want to be potentially bottlenecked down the line. Yay or nay?

    As for CPU, I've read all about how the i7 is only necessary for people who do intensive graphics-based activities and the like. That said, if we disregard that the i7's features aren't useful for everyone, the base 2.9GHz Quad-core Intel Core i5 (Turbo Boost up to 3.6GHz) is still less powerful in Ghz than the 3.1GHz Quad-core Intel Core i7 (Turbo Boost up to 3.9GHz). I guess my main question is, would there ever be a point when that extra bit of CPU grunt would come in handy for me? Or is it REALLY only for the kinds of people described above?

    Thanks for the help. Any further tips and info is much appreciated!
  2. macrumors 6502

    Jun 12, 2012
    Look at my sig, my workflow and computing needs are similar to yours. I went with the RAM upgrade over the CPU. Unless you do something that really stresses an i7, those extra cores just sit idle. Like you've mentioned, the i5 can turbo boost to 3.6 GHz, and that should be plenty for your needs. The RAM could be a bottleneck in the future, so it's best to max that out. If you're tight on cash, you could forgo the RAM and CPU as your workflow doesn't really justify an upgrade in either.
  3. macrumors 6502a


    Jul 10, 2009
    IMO, at this point, you almost certainly will not need either the i7 or the RAM. However, since you want this future proof, I would get the RAM as the system requirements for future software are likely to continue skyrocketing.

    I hope I don't offend anyone, but unless you genuinely need the CPU power for your current workflow, it is utterly stupid to get better CPUs than required. My reasons for this are that the real-world gains, regardless of synthetic benchmarks, are next to nil, and even benchmark #s aren't that substantial on a per dollar basis. You'll still have four cores with the i5, just not the HT and some other features. Also, in a year or two, the entry-level product will be more powerful than the high-end today. In light of this, it's always best to buy the cheapest thing that actually meets your needs, no less and no more.

    You won't miss those few extra megahertz. On the other hand, you will save $400 that could be put to getting your RAM or a nice shiny SSD, which will certainly have a noticeable improvement to your computer's performance. Speaking of RAM, NEVER ever buy RAM from Apple. Intel systems aren't finicky like the old PowerPC ones were with brand, and DDR3 is cheaper than dirt.

    Do you mind if I ask why you aren't considering the 27"? I personally love it, 1080p is just not enough usable real-estate for me. If you're not dead set on the iMac form factor, you might wish to consider a Mac Mini instead, which also has a small footprint and you could use the savings to get a killer display.

    EDIT: I just remembered the 21" is now no longer user-upgradeable as far as RAM... Apple's $200 upgrade is a tough pill to swallow. I should have read the OP more carefully instead of skimming, as I kind of repeated what you already know. Oops!
  4. thread starter macrumors newbie

    Sep 25, 2012
    Thanks for the responses!

    Is there a chance though that hyperthreading will be more widespread and utlised by consumer applications/games in that "year or two"? Much like with quad-core CPUs (which as far as I know were't initially utilised by a lot of software upon release)?

    As you noted, yeah, there's no option to *not* buy RAM from Apple. Even though it's $200 though, perhaps the real world benefits going forward will be worth it? Just to provide an example, my old MPB currently has a multi-tabbed browser open as well as a few other programs, and in total it's using 3.95GB of its 4GB total RAM, with 2.27GB Page Ins and 3.45GB Page outs. Can you gather anything from that? (I'm not the most technically proficient here!).

    Mainly due to the size. The display really is just too big for me, and I find that a 21.5" is just right. And even though it doesn't come with a 680MX, when it comes to native resolution gaming isn't the 650m *kinda* just as good considering the screen sizes and the fact that the 680MX has to accommodate for that massive panel?

    As for Mac Mini, I just find the iMac more convenient, as well as the fact that it's got a bit more grunt.
  5. thread starter macrumors newbie

    Sep 25, 2012
    Anyone able to offer any further info? Cheers.
  6. macrumors 6502a


    Jul 10, 2009
    If I'm not mistaken, isn't the quad-core i7 Mac Mini a good deal more powerful than the quad i5 iMac (and only slightly less than the quad i7 iMac)? Of course, since you want an iMac, I am in no way telling you what to buy, as the decision is yours.

    Just throwing out a significantly cheaper alternative (800 vs 1500, though you'll need a display but they're cheap) as it provides a better CPU, upgradeable HD/RAM, and might be suitable based on your stated needs and usage scenarios.
  7. macrumors 6502a

    Mar 15, 2011
    If you can, the fusion drive is a much better upgrade than the i7 or RAM.

    i7 is really not needed.

    RAM: Maybe, if you really want to spend the money, personally, 8 GB should be plenty unless you are editing video heavily etc. For casual use, you should really not be using more than 5 or your 8 GB.
  8. macrumors newbie

    Oct 1, 2012
    I wonder aswell

    I'm facing this question too.

    I'm a graphic design student (mainly use Adobe Ai, Id, Ps and sometimes Fl & Dw) and occasionally a game (gw2).
    I currently use a mid-2010 13" MBp (stats below)
    The main reasons to buy an iMac are to have a bigger screen to work on and to take some strain of my MBp (especially with gw2, as i am below stats).

    But do i really need a maxed out 21,5" or can i go with 8gb ram & i5 processor?
    (note: 27" is totally out of the question, way too big and costly for me)
  9. thread starter macrumors newbie

    Sep 25, 2012
    I ended up getting the 16GB RAM + Fusion Drive. I decided to stick with an i5 and not go with the i7 since as most people say, many applications don't use up that extra grunt.

    Although the price of the RAM was tough to swallow due to Apple being, well, Apple, I decided that since it wasn't user upgradeable, I would be better off getting it there and then. And since applications will only use more RAM going ahead into the future, I thought it was a good investment.

    Thanks for your help all.
  10. macrumors 68040

    Feb 13, 2012
    Perth, Western Australia
    Do you need a computer at all?

    Who knows.

    "need" is a very subjective word.

    As to best bang for buck, 16gb is where it's at.
  11. macrumors 6502a

    Jun 24, 2012
    You are mistaken.

    The i7 in the Mini is a 3615/3620QM mobile i7 at 2.3/2.6 GHz. The i5 in the iMac is a desktop 3470S 2.9 GHz i5. The desktop i5 is more powerful.

    Also, to address HT, there is very little consumer use for it. You already know if you need HT, so usually if you have to ask the answer is that you don't. For the bulk of daily computing tasks the cost of the i7 over the i5 is simply not worth it.
  12. macrumors 6502a


    Jul 10, 2009
    The Mac Mini has the 3615QM and the 3720QM. I'm not sure where you're getting your numbers from, but Geekbench says otherwise. The 3770 top-end iMac is the most powerful, but even then, it barely edges out the 3720M. Ivy Bridge was not kind to desktops, as they focused too much on dropping desktop TDP from 95W down to the 77W range, which is great for laptops, less so for desktops, where performance is paramount and power/battery life is not an issue.

    But either way, the entry-level and mid-level iMacs have surprisingly low performance compared to the Minis and the MacBook Pros. That said, every computer fits its own niche and the iMac is unique in the role it fills in Apple's lineup and can't really be substituted if an all-in-one is what someone needs.

  13. macrumors 6502a

    Jun 24, 2012
    Ah, yes - look at all those HT-aware benchmarks!

    This is what I was talking about - the i7 is shown in a flattering light by those benchmarks due to the ability to run 8 threads.

    For the bulk of what you're going to do with it, unless you're doing embarrassingly parallel processing (like benchmarking the CPU or encoding video) the mobile i7 is not as powerful as the i5 in the iMac - a result shown in the very benchmarks you have posted.

    So, "where I'm getting my numbers from" is the benchmarks you have posted to try and discredit me. I assume you've looked at them.
  14. macrumors G3

    Jul 23, 2002
    Sol III - Terra
    I'd say go for the 16GB of ram. It's not designed to be user upgradable and would probably affect the warranty. Also, if you are running multiple things, more memory is always better.

    I'm not sure you need the i7.
  15. macrumors 6502a


    Jul 10, 2009
    Calm down, buddy. No need to get your junk tied in a knot, none of that was a personal attack. No one is trying to "discredit you". I am aware that it is superior in single-threaded, but it's not drastically better at that, and you'd be surprised at how many programs do in fact take advantage of multiple threads. Perhaps my usage scenario is more representative of this than most as a computational biologist, but I program a lot and am pretty keen on the state of the software industry.

    My point stands regardless -- the iMac is a very poor value on a performance basis compared to the Mac Mini. Nothing I said is inaccurate or unsubstantiated. If you need or want the iMac form factor or dedicated graphics, then buy it. Otherwise, your money goes much farther with a Mini.
  16. cirus, Jan 10, 2013
    Last edited: Jan 10, 2013

    macrumors 6502a

    Mar 15, 2011
    The desktop i5 runs at 2.9 Ghz, with turbo to 3.6 Ghz. The mobile i7 3720m also turbos to 3.6 Ghz. The two will have very very close single thread performance (within 5%). The mobile processor however, will have hyperthreading and so will be significantly better at encoding, or tasks that require more than 4 cores (which admittedly are few, but they are there). Mobile i7's are more powerful than top end i5 desktop (i5-3570) in multithread performance.

    You do lose the gt 650m which is about 3x more powerful than the hd 4000 so for moderate gaming don't go for the mini.

    Edit: The geekbench scores show the imac winning by about 5-10% against the 2.3/3.3 Ghz i7 mini. The 2.6/3.6 mini will be directly comparable to the desktop i5.
  17. macrumors 68020


    Jan 2, 2009
    people are so weird. you visit the other forums where ram is upgradable for their device and everyone is like oh yea im putting 16gb in right away it makes such a difference on and on. Then this thread on something you cant upgrade people are like oh no 8gb is enough. Ive yet to see on any other device besides the air that people have been happy with 8gb. they always put in 16 gb "later".

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