Is it true what they say "You Can Never Have Enough RAM" ?

Discussion in 'Mac Pro' started by Anto38x, Aug 13, 2009.

  1. Anto38x macrumors member

    Anto38x

    Joined:
    Aug 19, 2006
    Location:
    Cork, Ireland
    #1
    Hi guys....
    Just wondering of with the near imminent release of Snow Leopard which promises greater RAM usage... would it be wise to get more RAM. I'm a graphic designer currently operating Quark 8 + Creative Suite CS4 + iLife... I currently have a MacPro Dual 3GHz running 10.5.8 with 8GB and I'm contemplating going all the way to 16GB.

    Will it make a difference ? and would it be a BIG DIFFERENCE or MINIMAL ?
    Will it be money well spent (as RAM is very cheap at present compared to a new MacPro) ?
    Will Snow Leopard really make a difference ?

    Any and all comments most welcome...


    Yours sincerely,
    Anthony
    Irish MacUser and MacAddict
     
  2. Chad H macrumors 6502a

    Chad H

    Joined:
    Feb 13, 2008
    Location:
    Auburn, AL
    #2
    I believe that saying to be misleading. How much of your RAM are you currently using? Also, you need to look at benchmarks for which memory combo will yield more RAM and greater performance. For isntance, 6GB of RAM in my quad is faster than 8GB.
     
  3. Loa macrumors 65816

    Loa

    Joined:
    May 5, 2003
    Location:
    Québec
    #3
    Indeed, for the simple reason that we can finally get more RAM than the system actually needs.

    I'd like to have more info and results on that. I did this test on my 2009 2.66 quad using PS4. 8GB is better than 6GB in all the real-world tests I've been able to run, and has the same performance in artificial (not representative of real work) tests. In fact, in PS4, I've never seen 6GB being faster than 8GB.

    Using a benchmark to measure raw RAM speed, 6GB *will* be faster than 8GB on the Nehalems, but I'm not seeing the same thing in PS4, at least on my quad.

    If you have experienced a faster 6GB in PS4, I'll gladly remove my 4th chip! :)

    Loa
     
  4. Chad H macrumors 6502a

    Chad H

    Joined:
    Feb 13, 2008
    Location:
    Auburn, AL
    #4
    This was strictly using xBench and using OWC's website as comparison. I will pull it up though. I will tell you I'm probably wrong on this. I'm getting that feeling. :)
     
  5. surflordca macrumors 6502a

    surflordca

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    Nov 16, 2007
    Location:
    Ontario, Canada
    #5
    Yea but you would never notice it...
     
  6. gugucom macrumors 68020

    gugucom

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    May 21, 2009
    Location:
    Munich, Germany
    #6
    RAM that you don't need still burns electric power.
     
  7. BENI macrumors regular

    BENI

    Joined:
    Jun 27, 2009
    #7
    no - don't get more than you will use cos it does interfere with the processors and other system monitering once you get a diss proprtionate amount to the CPU speed. anyway it will just sit there mostly empty having burned a hole in your pocket once you have more than 16.

    DO NOT PUT IN UN EVEN RAM - like a 2gb and 4gb in the same computer always balance.
     
  8. irishgrizzly macrumors 65816

    irishgrizzly

    Joined:
    May 15, 2006
    #8
    What is your page in/out ratio after a days work?
     
  9. Tesselator macrumors 601

    Tesselator

    Joined:
    Jan 9, 2008
    Location:
    Japan
    #9
    Well, the OS with just a few apps can EASILY use up to 32 GB without even breaking a sweat! Many Nehalem motherboards can now be populated to 144GB and I for sure want one! 44GB for the OS and apps and 100GB for a RAM drive.

    A RAM drive is faster than any SSD currently available. Here's the (slow) 2006 RAM in a small RAM drive:

    http://forums.macrumors.com/showpost.php?p=7838758&postcount=4


    With 4 GB RAM after about 4 to 6 hours of using your MacPro it starts to get a little sluggish. At 8 GB the time goes up to about 8 to 10 hours of work. At 12 GB ~ 16 GB the machine stays smooth for a about 24 to 30 hours of work. I guess 32 GB would give you a week of uptime under heavy work conditions. There is a noticeable speed difference between at these intervals. You may not notice the speed difference right after booting but you sure will after working with a few large datas. Video editing, multiple image edits, undos, etc. etc. all fill up your RAM and and after full-ish things begin to slow WAY down. If you're working on a few 12 ~ 24 MPx images this gets used up VERY fast - remember each undo is the size of the image previous to the edit being undone. Video is worse in some cases. I'm at 12 GB now and I see it hitting max almost every time I "work".

    Power isn't a big issue. a 1GB stick takes about the same power as a 16GB stick and each stick is only about 4W.
     
  10. bearcatrp macrumors 68000

    Joined:
    Sep 24, 2008
    Location:
    Boon Docks USA
    #10
    Hey Tess, I remember doing this in DOS 3 years ago but haven't even thought about this in a mac. By creating this, will OS X use this or do you have to specify certain applications to use this? I would like to set up 4gb for VM to use thinking the little page outs I get will go there. Make sense?
     
  11. Loa macrumors 65816

    Loa

    Joined:
    May 5, 2003
    Location:
    Québec
    #11
    Doesn't OS X use page-outs when the physical RAM is full? IF so, how would a RAM disk help?

    Loa
     
  12. Tesselator macrumors 601

    Tesselator

    Joined:
    Jan 9, 2008
    Location:
    Japan
    #12
    I think he means as a scratch-disk. At least that's the only thing that makes sense to me. Yeah, a RAM drive acts like any other hard drive. There's some info in the post I linked to about different ways to set one up and additionally an www.ask.com search will find more. If OS X is enough like Ubuntu or other linuxes you can also get it to restore a system partition to the RAM drive and operate the OS from there. It's like booting from it but you actually need a boot HDD to make it work - And also a large enough RAM Drive (which I guess we don't have with only 32 GB possible in 2006 ~ 2008 Mac Pros).
     
  13. Eidorian macrumors Penryn

    Eidorian

    Joined:
    Mar 23, 2005
    Location:
    Indianapolis
    #13
    Only if you can't afford it.

    2 x 2 GB of DDR2-667 SODIMM was $79.99 back in 2007. It's half of that now for DDR2-800.

    On the FB-DIMM front your prices are only going to go up due to lower demand now that Nehalem and DDR3 are the current leaders.
     
  14. bearcatrp macrumors 68000

    Joined:
    Sep 24, 2008
    Location:
    Boon Docks USA
    #14
    No, not a scratch disk. I was thinking of a way to direct VM to ram, similar to a ram disk set up, instead of the data going to the hard disk again. Read about it not long ago. I'll have to go find it again. My page outs don't usually go beyond 5mb but still thats a lag. But maybe snow leopard going full 64 bit will change things.
     
  15. nanofrog macrumors G4

    Joined:
    May 6, 2008
    #15
    There's usually a setting you can adjust for the memory available to each VM session.
     
  16. Tesselator macrumors 601

    Tesselator

    Joined:
    Jan 9, 2008
    Location:
    Japan
    #16
    VM to a RAM disk, yeah, that can be done. But I dunno how much sense that would make. System VM only happens when there's not enough RAM. And it considers total available memory space. It's not like a 32-bit app's proprietary VM (AKA: Scratch) where it's limited to 3GB or whatever before it goes to disk.

    So you would be decreasing the amount of RAM in order to speed it up in cases where there wasn't enough RAM. Ummm... :p
     
  17. bearcatrp macrumors 68000

    Joined:
    Sep 24, 2008
    Location:
    Boon Docks USA
    #17
    Well, lets consider the 3gb limit. When a program does exceed this, it does write to vm, aka hard disk. If your system has say 16gb, and your page outs are never over say less that 500mb, sending that vm to a ram disk per say would be quicker since it wouldn't have to spin up another disk or write to the same disk again. Since ram is way faster than a hard disk, I would assume this would be an improvement. If you never have page outs, then this wouldnt help. When applications get rewritten to 64 bit, then this problem should be resolved provided the system has sufficient ram. My guess that programs will have a limit even in 64 bit to ensure it doesn't hog system resources. Hopefully Snow Leopard will address the limitations on 32 bit programs and allow them to exceed the 3gb limit. Not sure if thats possible. If anyone here running the beta on SL, can you chime in on running 32 bit programs, preferably using photo shop or imovie and tell us if you still get page outs with heavy use.
     
  18. Tesselator macrumors 601

    Tesselator

    Joined:
    Jan 9, 2008
    Location:
    Japan
    #18
    It does? OK. I only have like two programs that have this limit and neither of them act like that.

    For Photoshop it's 3GB per image and when that limit is hit it writes to it's scratch drive - not the systems VM space. It hits the system's VM space when all loaded files plus undo and etc. exceed the amount of total system RAM.
     

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