MacBook Pro/Mac Mini RAM/SSD advice

Discussion in 'MacBook Pro' started by Sub-o, Mar 25, 2014.

  1. Sub-o macrumors newbie

    Joined:
    Jan 28, 2011
    Location:
    Ireland
    #1
    Hi guys,
    Sorry for starting a new thread, but I can't find an answer to this.
    I'm trying to find out if my machine is running slowly because of a lack of RAM.
    And to be clear, my reluctance to upgrade the RAM is purely financial as I've just purchased a late '09 Mini and put in a WD Black 750gb and a used set of 4gb RAM, which was very cheap! The machine is to serve as the media hub/work station.
    It's running OSX 10.9. Thanks to the forum the hardware install and cloning process went without a hitch.

    But it just shows that my Early 2011 MacBook Pro 13" is running quite slow, with a lot of "beach balls". It still has the stock 4GB Ram & 320GB 5200rpm HDD. My usage is just iTunes, Firefox, iPhoto,Office apps, etc with occasional video conversion.
    The obvious and easiest thing to do is go to 8GB RAM, 16GB is still too expensive.
    But as I said, that can't happen for a while.....
    But when I watch Activity Monitor, Swap remains at zero. Virtual Memory can increase with a lot of apps open.
    Under the "top" command in Terminal, it shows 0(0) in both pages in & pages out.
    The Mini is exactly the same and I'm thinking due to the 7200GB HDD, it just feels snappier.

    So finally the question(!):

    Am I not taxing the RAM?
    Would it make more sense to plan and go for an SSD, as it's the drive that's the bottleneck not the RAM.
    I don't here too many complaints from early MacBook Air users who are stuck with 2GB RAM while still running OSX 10.9.

    Eventually I'd like to whatever I do to my MacBook, to the Mini.
    Thanks!
     
  2. yjchua95, Mar 25, 2014
    Last edited: Mar 25, 2014

    yjchua95 macrumors 604

    Joined:
    Apr 23, 2011
    Location:
    GVA, KUL, MEL (current), ZQN
    #2
    SSD first, RAM later, since the bottleneck usually isn't the RAM.
     
  3. Sub-o thread starter macrumors newbie

    Joined:
    Jan 28, 2011
    Location:
    Ireland
    #3
    Thanks for such a fast reply.
    It just goes against my belief that max RAM is ALWAYS the way to go....
    I really doubted I was interpreting the data correctly.....

    A 120GB M500 from Crucial, is the same price or less than doubling the RAM. A 240GB is only €100, so I think I'll aim for that, with either the 320GB in an optical bay caddy or the mini's old 160GB, with the 320GB being a dedicated CCC clone and Time Machine backup.
    As I don't have to back up photos or music because that's all taken care of by the Mini.
    The forum has been a fantastic resource and I'm REALLY delighted with the set up and soon both machines will have both a physical CCC clone & Time Machine as well as online backup....
    The Mini, with Forum assistance is a fabulous machine.
     
  4. yjchua95 macrumors 604

    Joined:
    Apr 23, 2011
    Location:
    GVA, KUL, MEL (current), ZQN
    #4
    By the way, to tell whether you're taxing the RAM or not, go open up Activity Monitor while you're doing your regular tasks and see the amount of swap used. If the swap used is quite high, you're taxing your RAM, and you'd have to upgrade the RAM to avoid damaging the SSD.

    Now, why can paging out a high amount of RAM damage an SSD?

    Upgrading to an SSD prior to installing the proper amount of RAM would reduce the life of the SSD. First, with inadequate RAM, the SSD will be utilized as virtual memory, offsetting the lack of physical RAM. By doing this, the computer will write tasks that are normally written to RAM, to the SSD. Because SSDs have only a finite amount of writes available to each transistor, you'll effectively shorten its lifetime, and increase the risk of data loss. Additionally, even fast SSDs pale in comparison to the speed of RAM – ~500MB/s in SSDs vs. ~23 GB/s in RAM (@1333 MHz). Therefore, the best solution would be to install the appropriate amount of RAM first, followed by an SSD upgrade. Once the proper amount of RAM is installed, an SSD will truly shine.
     
  5. Sub-o thread starter macrumors newbie

    Joined:
    Jan 28, 2011
    Location:
    Ireland
    #5
    Yup, thanks.....I was up to speed on why to go RAM first.
    I did the tests, last night watching Activity Monitor & Terminal. I opened all the most used apps and there was zero Swap used in Activity Monitor and 0(0) in pages in and pages out in Terminal.
    I was truly surprised and hence why I was doubting my interpretation of the data. I would have considered 4GB RAM insufficient, but it looks as if it's adequate for me.
    I'm curious as to why, the Virtual Memory increases under load. Is the OS sticking the extra non viewed apps in there and returning them to RAM as soon as they're on screen?
     
  6. glenthompson macrumors 68000

    glenthompson

    Joined:
    Apr 27, 2011
    Location:
    Virginia
    #6
    In many cases, yes. Assume you have 2 programs, A & B, running at the same time. They both fit in memory. If you're actively using A and it needs more memory but none is available, more virtual memory gets allocated to it and the physical memory needed to support it is taken from program B's memory. The system chooses little used and unchanged pages of program B's memory to free. That way it doesn't have to swap them out to disk. When B needs them later, the system only has to reload them from disk. This saves the writes but not the reads. If the system has to free a changed page, it has to write it out first before giving it to A.

    Lots of programs use more memory as you do different things. Just look at a browser's memory usage as you open additional tabs or visit different sites. I've seen Firefox grow from a few hundred meg to over 1.5gb memory used.
     
  7. Sub-o thread starter macrumors newbie

    Joined:
    Jan 28, 2011
    Location:
    Ireland
    #7
    Thanks Glen....makes sense.....
     

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