Difference between rMBP 2.7 and 2.9 GHz processor

Discussion in 'Buying Tips and Advice' started by student4lyfe, Jul 2, 2015.

  1. student4lyfe macrumors newbie

    student4lyfe

    Joined:
    Jul 2, 2015
    #1
    Hi everyone,
    First post here, I'm about to convert from PC to Mac! WHOAAAAA

    Anyway, I'm set on a 2015 13' rMBP, going to max out 16GM RAM and up the SSD to 256GB because I want to future-proof it for at least 5 years. I know RAM is most important, and 256GB is more than fine (at 4+ yrs on PC and only used ~100GB memory). I'm a student, so I get the discount, and also take good care of my stuff. Previous PC was good for 6 yrs.

    Now about processing power, I don't think it's worth the $270 to upgrade from i5 2.7GHz to i7 3.1GHz, but what do you all think about $90 to upgrade to the i5 2.9GHz. I've seen the CPU clocking on various sites and the 0.2 GHz difference is about 5% faster. Trivial amount now, but will it matter in 5 years? Also $90 is an ehh not-huge amount and far from significant like the $270. Don't mind spending the $ but only if it matters.

    Battery life is important, and I was wondering if the 2.9 processor might use battery faster than 2.7 processor. Can't find a straight answer online.

    Appreciate any insights/opinions. Thanks!
     
  2. kapawozniak macrumors newbie

    Joined:
    Jul 1, 2015
    Location:
    London, UK
    #2
    Same scenario here, I want to buy a new 13" rMBP, and also the middle model. I can't really splash out on 16GB RAM unless I switch to the base 128GB configuration, and I think I might need some more storage, as I'm coming from a 1TB HDD PC and not used to using cloud to a large extent.
    I think that:
    1) Upgrade to dual-core i7 would give you at most 15% more power and is way too expensive to be worth it unless you're working on heavy video-editing, but then it's better to go with a 15" Pro.

    2) An upgraded i5 is based on the same architecture and its power uptake (28W if I remember correctly) should be the same as base model, either way it should not influence battery life too much. And even if, I suppose it would be a difference measured in minutes and MBP still has an amazing battery life.

    3) Not sure if such a small difference in processing power would actually mean anything even in a few years. Processors now are getting smaller and require less energy to power them, but they're not getting considerably faster. A quad-core Ivy Bridge i7 (from 2012) I have on my current PC is still quite on par with current-gen processors when it comes to processing speed, but takes up a lot more energy and requires more cooling.

    4) I'm not quite sure if processor clocking could also influence the behaviour of integrated graphics. Anyone?

    My question here is - is it better to go with 13" 128GB model with upgraded RAM (to 16GB) and processor (to 2.9 GHz i5) or to go for a base 256GB rMBP (8GB RAM, 2.7 Ghz) in terms of making it more of a machine for the next 4-5 years?
     
  3. kohlson macrumors 6502a

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    #3
     
  4. kohlson macrumors 6502a

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    Apr 23, 2010
    #4
    I think it's unlikely you would notice the performance difference in the CPUs in day-to-day use. I think any reduction in battery life will be nearly impossible to measure -- too many other variables. But if you are future-proofing, more is better. Who knows what the next few years will hold for you? Requirement to run Windows VM? Photo/video editing?
     
  5. talmy macrumors 601

    talmy

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    Location:
    Oregon
    #5
    It will still be just a 5% difference in 2020. You would only see the 5% difference in a computationally bound program and then you would need a stopwatch to measure it. It's only worth it if you make money from the computer, certainly not for student or pleasure use.

    The mystery of future proofing! The alternative is to buy what you need now and if you need more later (you won't necessarily will) just buy a new computer. In my personal experience, I'd go with 8GB RAM since for me 4GB is enough now, but I'd get 512GB SSD. But I'm not you and you are not me.

    Modern processors consume little power when idle so the 2.9 is unlikely to use more power than the 2.7 when idle. When active it could use more power, but it will also get the work done faster. So bottom line is it really doesn't make much difference. Note that the additional memory will use more power.
     
  6. SSD-GUY macrumors 6502a

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    Sep 20, 2012
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    London, UK
    #6
    You will not notice the difference in day to day tasks. For tasks where the processor "may" come in handy, such as video rendering/converting etc, you will probably see few seconds of difference, if that.

    I would upgrade the SSD to 512 using the same money, as the 512 SSD's I think have slightly faster read/write times, and even if they didn't, as the SSDs are not user upgradable, when it comes to resale time in a few years, you will get more money for it compared to 0.2ghz increase in speed.
     
  7. casperes1996 macrumors 65816

    casperes1996

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    Horsens, Denmark
    #7
    Contrary to what @talmy said, the extra RAM won't use more power. Well, sort of. If you have 8gb, and you use +4, it'll use more than if you have 16gb and us -8gb, since only one stick will be active, and the other can power off. If you use both sticks, the power consumption difference is so minuscule that it would be impossible to notice.
    The processor difference matters little now or in 5 years. The jump to an i7 is much bigger because of things like extra L3 cache, but for light workloads, it won't really matter. As @SSD-GUY said, the 512gb SSD is slightly faster. In fact, bigger SSDs usually are. SSDs also run dramatically faster if they have a bit of free space. More RAM can be very useful on OS X however, since the OS can put stuff you might need in the RAM, to speed up loading of said things, even if you don't actively use them right now. Neither RAM n'or SSD is upgradable in the future, without replacing the whole motherboard (Or being really good with tiny bits, and having access to specialised tools... I mean everything's possible). With the speed of the SSD regardless of size, RAM is the most important in securing smooth operation in the future, but files and such get larger with time as well, so making sure you have enough storage can be important as well. You could however always get an external SSD/HDD to offload data to. That's what I do. (1tb Fusion Drive + ever expanding storage array for storing old Final Cut files). In the end however, it all comes down to usage. If you use RAM hungry apps, get more RAM. If you have a lot of large files, get more storage. The apps and OS's of the future won't prefer one over the other to any great extend, when we're talking about the differences in speed and capacity we are now.

    Regarding power consumption, it'll be the same corresponding to the same calculation-output. It'll use a bit more power when crunching at max power, but will also finish it's tasks quicker, and idle again. So in the end, it's a matter of what tasks you have it do. If it's running an endless loop all day stresses the CPU to the max, the battery will drain faster. If you perform short burst actions, it might last a minute longer.

    @kapawozniak asked about integrated graphics, and to anser that, yes. The CPU clock can impact the behaviour, but not directly. The GPUs in both configurations are clocked the same (I believe 300mhz). the CPUs however could send the draw calls at different speeds, meaning the higher clocked one could still have better graphics performance. It might also have better binning (which going back to the battery thing, might mean slightly better perf/watt)
     
  8. student4lyfe thread starter macrumors newbie

    student4lyfe

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    Jul 2, 2015
    #8
    Thanks everyone, think I'm going to go with the 2.9 GHz, 16GB RAM, 256GB SSD. Definitely wanted to max out RAM since that seems to be the biggest limiting factor for future-proofing. If I could have gotten a 512GB SSD with the 2.7GHz, I might have gone with it (probably not), but the 512GB SSD comes with the 2.9GHz as baseline.

    I'm a medical/graduate student with an interest in investing/trading, so I like to have a lot of tabs going while running computational biology analyses. SSD capacity isn't a big deal since I don't do much with media, just storing recreational photos, some music, no video. After 4+ years, I'm only using 100GB on my current computer.

    Since this is the "Buying Info" forum, I thought I'd share a few other hacks.
    State tax holidays - often in summer, can knock off ~$100 in price.
    Educational pricing - saves me $130
    Back-to-school promotion sometime this summer - $100 apple store gift card
    US Bank Cash+ credit card has a 5% cash back at Best Buy/Apple Store (~$80 for me) AND also a $100 signup bonus.
     
  9. hiddenmarkov macrumors 6502a

    Joined:
    Mar 12, 2014
    Location:
    Japan
    #9

    What application(s) are you running for the analyses? If windows based with no Mac OS alternatives you may want the larger drive for the VM to support them until a replacement found. You'd be eating for 2 as it were with the virtual support. And windows can eat up some space for just base OS plus whatever you tack on to it. I'd highly advise going down your list of "must have" apps to make sure the software conversion is good and no "legacy" app issues as it were.

    If your software has a MacOS version or is of the CLI kind (say HMMER if into that area) you should be good though. Many bioinformatics tools used prior had a mac package available or built off source no issues. Be aware with CLI installs you will need to tack on xcode and its cli tools to get cli commands like make and such to build off source. Not sure if the cli tools can be installed separate (I wanted the ide as well)...if not xcode eats up some space with ide and docs installed.
     
  10. Orr macrumors 6502

    Orr

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    Oct 8, 2013
    #10
    The only discernible difference is wasting $90 more.
     
  11. casperes1996 macrumors 65816

    casperes1996

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    #11
    Hope you enjoy it!
     
  12. student4lyfe thread starter macrumors newbie

    student4lyfe

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    Jul 2, 2015
    #12
    Hi everyone,
    Actually I'm gonna go with the 2.7GHz processor while keeping the 16GB RAM and 256 SSD. Sure it would have been nice to know my processor is a bit faster, but if I can't really tell the difference, why's that worth $90? I don't do any video/photo editing or play video games.

    A last question though, so in my research I work with large genomic data sets from DNA sequencing experiments, and I'm often opening multiple files in the 1GB ballpark at a time. It's my understanding that RAM would be the major determinant here and not processor speed right? SSD capacity isn't the issue since these files are all stored on a server.
     
  13. jerwin macrumors 65816

    Joined:
    Jun 13, 2015
    #13
    What software programs do you use to manipulate these data sets? Surely there have been papers written on how to optimally configure a workstation or server node for this purpose.
     
  14. meyer1131 macrumors regular

    Joined:
    Mar 6, 2008
    #14

    Just bought this exact machine
     
  15. ApfelKuchen macrumors 68020

    Joined:
    Aug 28, 2012
    Location:
    Between the coasts
    #15
    I'd definitely not pay $90 for a 2% improvement in processor speed.

    I have a feeling you'll be wasting the money you spend on 16 GB RAM. I might have put that money into more SSD instead. But without knowing how the apps you'll be using utilize RAM, we're both just shooting in the dark. Another factor in this issue is that OS X uses RAM compression - 8 GB of physical RAM in Mac goes farther than it does in Windows.

    Overall, "future proofing" isn't what it used to be. RAM and storage requirements are not doubling every 5 years, as they once seemed to. I think smart phones and tablets have done a lot to shift developers' emphasis from feature bloat to efficiency, and that spills over into PCs/Macs, as the trend there is also towards power-efficient, lightweight, and compact hardware.

    Meantime, the shift from mechanical HDD to SSD means that, if page-out of RAM to SSD is necessary, the speed penalty is far less than it would have been with an HDD.

    Of course, since RAM is not upgradable but you can always tack on an external HDD or SSD, insufficient RAM would be the bigger mistake. Just do a bit more research, to see what your particular apps really need. (I have around 400 GB in image and music files, so 256 GB always seems small to me.)
     
  16. casperes1996 macrumors 65816

    casperes1996

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    Horsens, Denmark
    #16
    As someone else said, this could depend a bit on the software you use. That said, I'm willing to bet my first baby you're correct that RAM will matter way more. The processor speed difference is minor, but if your files fill all your RAM, and you have to page to the disk, you go from 25.5gb/s (roughly) to roughly 1gb/s or less of data being sent to the CPU. But this is where the SSD comes in to play, because if you absolutely have to page to the disk, the larger SSD will be a bit faster. Anyhow, extra RAM will do you good, anything else is a luxury that you don't really need or will see much benefit of. Personally I can easily fill 16gigs of RAM on my Mac, even with compression though.
     
  17. RGPphotog macrumors member

    RGPphotog

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    Orlando FL
    #17
    More RAM is NEVER a waste of money, especially if you plan on keeping the device long-term. Ever looked at how much RAM Safari & Chrome use up while browsing? I have 16GB in my MacBook Pro and I STILL see RAM compression and file swapping (to the SSD). Never skimp on RAM. I would have gotten 24GB/32GB of RAM if it were available. Of course that might be overkill for some of you guys, but from my experience – when I'm NOT working on photo/video editing – I'd consider 16GB as the recommended minimum for 2015, for the average user. Especially for a computer that can't be RAM-upgraded later on. Just running OS X can easily eat up over 4GB RAM, if you really pay attention to your RAM use. My old MBP maxed out at 4GB of ram, and with Yosemite I'm compressing RAM as soon as the computer turns on!

    At the moment I've got one window in Safari (this page), 1Password, and Mail running... 5.5GB Ram of 16GB consumed. And 43MB of swap (which isn't bad, but it frequently goes into the hundreds of MB. Though to be fair that's usually when I'm working in Lightroom.)
     
  18. Samuelsan2001 macrumors 603

    Joined:
    Oct 24, 2013
    #18
    Macs use as much ram as they can, with the same use case on 4Gb it would be still absolutely fine and show you using much less, your mac will load all sorts of stuff to RAM "just in case" that doesn't mean it's needed in any way.
     
  19. RGPphotog macrumors member

    RGPphotog

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    #19
    That's not my real world experience. Again, my old MPB with 4GB RAM would use the same amount of "RAM", though about 1GB of it would be compressed. It would show me 5-6GB "used".
     
  20. Samuelsan2001 macrumors 603

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    Oct 24, 2013
    #20
    Total opposite of my experience my 2010 with 4GB worked fine the upgrade to 8Gb made no difference but the SSD made all the difference.
     
  21. talmy macrumors 601

    talmy

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    Oregon
    #21
    One's experience is totally dependent on usage, which makes these threads pretty much useless unless the OP states precisely what they are doing. And for that Activity Monitor can pretty much reveal the answers. Memory pressure high? You need more RAM. CPU usage high? You need a better CPU (perhaps quad core if the CPU pane shows all cores being hit hard). Do you hear disk activity or do you boot up and/or launch apps frequently? Get an SSD. All your time browsing the web? Get faster Internet service, your computer is fine.

    My old MacBook was sitting at 100% CPU usage for hours. A 15" quad core MBP made a world of difference. Adding an SSD to a Mac mini I use at work (many apps and programming) made it faster than a Xeon-equipted HP workstation I was given. Adding an SSD to my server mini was a waste -- only made booting, which I end up doing only once every month or two, much faster, but that wasn't normal use. But more RAM helped since excess RAM is used for disk caching and I've got 10TB of disks on that system. YMMV.
     
  22. Samuelsan2001 macrumors 603

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    Oct 24, 2013
    #22
    Talmy thats really my point many people on here just automatically say get as much ram as you can or get an ssd without any real investigation. I was just pointing out that most people don't need anywhere near 16gb, despite what the people on this forum say.

    Great post though, I wish I'd written it.
     
  23. jerwin macrumors 65816

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    #23
  24. casperes1996 macrumors 65816

    casperes1996

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    #24
    Agreed, but I do believe our OP would benefit greatly from the extra RAM. This is pretty much guess work, since I've never worked with software like what he describes, but I think I'm fairly good at guessing in this arena. I also think that to the average user, SSDs make a world of a difference, even if they don't to everyone.
     
  25. student4lyfe thread starter macrumors newbie

    student4lyfe

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    Jul 2, 2015
    #25
    Yep, I'm definitely going to be doing a lot of RNA-seq and ChIP-seq analysis, but most of the heavy lifting will be done by our lab's remote server. I'll be using the rMBP for data manipulation, which requires loading several 1GB files at a time. A Mac will be fine for my needs since most of my lab's computers are Macs, and people mostly have Airs and Pros as their supplemental personal computers.

    Thanks for helping me to save $90 on the processor upgrade everyone. I do plan to get the 256GB SSD and max out the 16GB RAM because of the large files I'm working with, and future software requirements will inevitably rise. With the educational discount, state tax holiday, credit card bonus, and NIH fellowship, I should be able to get this rMBP for $700, maybe even $600 if the back-to-school promotion is a $100 store gift card. Cmon Apple, I'm still hoping for that BTS!
     

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