The 4 Gb RAM thing with G5s

Discussion in 'PowerPC Macs' started by leekohler, Dec 15, 2006.

  1. macrumors G5


    I've heard that G5s (especially dual-core/processor) really fly with 4 Gb RAM. Does anyone have one with this much RAM? If so, is it really worth the upgrade? I have dual-core G5 with 3.5 Gb RAM. It's great, but I do think it feels a bit choked at times. I would like to give it another Gig. What do you guys think? Worth it?
  2. macrumors 601


    What do you use it for?

    No, I dont think it would be worth adding extra 512 MB since you laready have impressive 3.5 GB. Matching RAM doesnt really improve performance on PPC Macs.

    BTW, every machine flyes with 4 gb RAM, if you can use all that memory of course ;)
  3. macrumors G5


    I'm an art director. I use it for photography and graphics, some video editing. It gets pushed hard, trust me. As for RAM not improving performance of PPCs, simply not true. I noticed a huge difference between 1 Gig and 3.5. I've just heard in several places that 4 is the magic number for G5s and was wondering what others' experiences have been.
  4. macrumors Penryn


    Check your RAM usage and page outs in Activity Monitor under normal usage. I doubt the extra 512 MB is going to make much of a difference.

    If you're using matching pairs of RAM you're not going to see much of a gain besides the extra 512 MB when you hit 4 GB.
  5. macrumors G5


    Using matching pairs is mandatory in the PowerMac G5s...
  6. macrumors Penryn


    I know.
  7. macrumors G5


    Thanks- and yes, I use all matching pairs. :)
  8. macrumors 68000


    I have 6GG in my G5 2.7 (I purchased it used and it was loaded up from previous owner) Note that pshop has a RAM max of 3GB or so; you may see more of an overall boost by getting some highspeed harddrives, just as the WD Raptor (which I also have, and REALLY speeds things up nicely)
  9. jtt
    macrumors regular

    So adding two 1 gig sticks with the factory 512 is a no no?
  10. macrumors 601



    Like, you have to use matching pairs, as you can't have one stick of 1GB just sitting there, it has to be, for 512MB, 2 256MB sticks, 1GB 2 512MB sticks, 3.5GB... 2x 1GB, 2 512MBs, and 2 256mbs.

    Get it?
  11. macrumors 601


    Uhh maybe you have to re-read my post more attentively...

    I said that extra 0.5 GB of RAM wouldn't mkae much of a difference, since you already have 3.5 GBs. Matching RAM (installing them in pairs) did not really help increase performace on PPC-based Macs. See benchmarks at The gains are usually 0-2%.

    And there's no "magic" number of RAM on any machine. If you heard that 4 GB is it in PMG5, it must be 4 1GB sticks, which in theory will give you maximum performance, if you're on a PM with 4 ram slots. This 4 1 GB sticks is also paired RAM.
  12. macrumors 68000


    4GB would be very nice, but I think your 3.5GB is more than fine. If you have the money and really want the extra 0.5GB, go ahead and get it, if not, you will be totally fine with 3.5GB.
  13. macrumors regular

    But why would you just go up 512MB? An upgrade to 5.5GB would be a big difference. Or is your revision of G5 limited to 4GB?

  14. macrumors 65816


    My impression is, that if you don't *know* if you need 4GB ram then you don't need 4GB of ram. I know what I need because I carefully monitor the Activity Monitor or Top and I can see if what I am doing is memory limited or not. If you are not memory limited then the extra 512MB is unlikely to help much. Make sense?
  15. macrumors 68000


    g5 dual 1.8 rev b with only 4 slots, and have 4gb (4 x 1gb) here. photoshop, dreamweaver, flash, firefox, itunes open all the time, and still have decent performance. can't imagine that 3.5gb would be any different though based on what i see in the activity monitor as i rarely get over 3gb.
  16. macrumors G5


    No I bought the last rev G5. I can get 16 Gigs in this baby. :) So yes, I should take it as high as I can go I guess. It's just that when burning DVDs, it maxes the RAM and then some. I should have said that earlier. Thanks for all the replies! :)
  17. MRU


    for anyone wondering if they need more ram.

    Activity monitor, under memory look at the page in/outs

    If you have a lot of page outs (the number after / ) then yes memory will help

    If you have /0 page outs then NO you dont need more memory as you are not using all the memory you have.

    Simple to check and a far better indicator than anyone here can tell if you need more memory as everyones usuage is different.

    I have 3GB in my MacPro and so far havent had a page out even though I'm using photoshop, entourage, painter IX.5 (all not universal), but I'm sure others will be using far more memory than me.
  18. macrumors 6502a


    well at that point the extra 512mb ram will not make much dfference...although i recently went from 1gig to 1.5 gig in my pm g5 and i can feel the difference in the extra 512mb
  19. macrumors 68030

    hi lee,

    if i were you, i would upgrade your video card. i would think it would help with the graphics big time. you've got enough ram.

    that's what i've heard before.
  20. macrumors G5


    Good thought! Thanks.
  21. macrumors 601


    Heh, the new videocard will make zero difference in 2D apps you work with. If you really want to waste some money, get a bigger monitor, or an iPod
  22. macrumors G5


    I hate to flog a deceased equine, but the machine in question is a PowerMac G5, installing in pairs is the only option, there is no "if you install in matching pairs then..." or "0-2%" comparison with non-paired RAM because you can't install a single.

    If you are saying there is no advantage to matching RAM across quads, that is, identical RAM in two matching pairs, then that is true, there isn't.

    If you are referring to the relative performance of 128-bit access in the the first generation iMac G5 by installing a matching pair, that is true but irrelevant to the PowerMac G5 because the architecture is totally different.
  23. macrumors 65816


    I have a dual 2.0GHz G5 with 4GB ram, and it has been plenty fast enough for anything that I have thrown at it. I mainly use it for audio production, running Logic and Live simultaneously (and occasionally Reason too), both for recording and mixing. I couldn't say whether it was significantly faster than 3.5Gb as I've had this configuration from the start, but it has run wonderfully so far.
  24. macrumors 601


    I know that the discussion is about PMG5 and I didnt say anything about iMac G5.

    You say that I can not, for example, install 3 1GB sticks in a PMG5? Does it has to be 2 1GB's and 2 512 MBs?
  25. macrumors 6502a


    4GB of ram is currently the sweet spot with OS X. Because of the way OS X handles virtual vs. physical ram, there is a diminishing returns with more than 4GB of ram. Even with lots of ram over 4GB, OS X keeps using more and more virtual ram rather than actual physical ram- getting worse and worse. Lots of Logic users have noticed this. Hopefully this will be fixed with 10.5.

    Still better than any windows machine could possibly dream of doing.

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