Intel Apps use more RAM than PPC Apps?

Discussion in 'Mac Pro' started by TheSpaz, Jan 30, 2007.

  1. TheSpaz macrumors 604


    Jun 20, 2005
    I have a mac pro at home and a G5 at work. The Mac Pro has 3GB of RAM and the G5 has only 1GB of RAM. I use MenuMeters both at work and at home. When I boot the G5 and start working, it shows 260MB of RAM already being used by the System, Suitcase, Safari and Illustrator CS 2. However, at home when I boot up my computer, it shows 500MB already in use without opening any Apps at all!... what the?

    I don't have anything usual running in the background at home or at work.
    I run more dashboard widgets on the G5. I run 1 widget on the Mac Pro (Swap Usage Widget)

    Once I get a few things running on the Mac Pro like Safari, iChat, EyeTV and stuff, my RAM usage goes easily up into the 1GB area.

    The other thing would be is... does it know it can use more RAM when more RAM is there to use? Like, does it see that I have 3GB and gives Applications an extra amount so they run smoother or something?
  2. iSee macrumors 68040


    Oct 25, 2004
    Can't answer all your questions definitively, but here are some things I do know:
    1. Rosetta (the part of Intel OS X that allows you to run PPC apps like Illustrator) is a real memory hog.

    2. The Mac OS X leaves old stuff in memory when it has extra room. I think it uses this as some sort of disk cache to speed up future operations if you happen to use something again. So it sort of expands to take over available memory as long as that memory isn't needed for something else.

    But all together that doesn't seem like enough stuff to justify the difference.
    For example, both your computers have lots of extra memory free at startup, So you would expect them to use up about the same amount.

    Hmmm.... Are these 2 computers running different versions of OS X?

    Maybe Intel specific components of OS X are large. Maybe Rosetta is launched at startup an is consuming RAM even before you launch any PPC apps?
  3. TheSpaz thread starter macrumors 604


    Jun 20, 2005
    Both computers are running Mac OS X 10.4.8. I forgot about Rosetta but, how do you even see if Rosetta is running or not. Which process is it? I find it amazing that I can be running Photoshop, Illustrator, Safari, Mail, Quark, Suitcase and the rest of the OS using less than 400MB of RAM, while the Mac Pro uses 500MB running nothing but the Finder.

    I forgot to mention, I checked Activity Monitor on my Mac Pro and all of the processes are "Intel". kernel_task uses up the most RAM but, I think that's normal. Does anyone else have both an Intel Mac and a PowerPC Mac to compare RAM usage on? Why is the Intel Mac RAM usage doubled? That's a big difference. I get by on 1GB of RAM at work easily. I hardly ever have page outs but, on 1GB of RAM on the Mac Pro, it's definitely not enough RAM. It's hard do anything without getting page outs. I also use a lot more Apps at work than at home too! I use a lot of design Apps at work while at home I only use iChat, Safari, EyeTV, Mail, iPhoto and sometimes Logic Express, iMovie and Toast 7. I'm planning on using Logic Express more as soon as my band is ready to do some heavy recording.
  4. trainguy77 macrumors 68040

    Nov 13, 2003
    I have noticed that too. My mac pro seems to take alot more ram then the emac. I think its just some changes related to switching to intel and will probably be worked out in 10.5
  5. TheSpaz thread starter macrumors 604


    Jun 20, 2005
    So I guess I'm really not going crazy then? When I get home I'm gonna check to see if I can remove a lot of my fonts. I hardly ever use most of the fonts that were installed. Also, I installed FrontRow on my Mac Pro, I can probably go ahead and uninstall that (somehow). I wonder if Rosetta is running constantly in the background or only when a PPC App is running because I only run one or two PPC Apps and I hardly ever run those.
  6. coolbits macrumors member

    Nov 1, 2006
    That is normal.. the more ram you have more gets filled up by caches to run programs faster...

    Unused ram is a waste...
  7. QCassidy352 macrumors G3


    Mar 20, 2003
    Bay Area
    I don't have a PPC mac anymore, but in my experience, Intel macs are huge RAM hogs compared to PPC macs. I wouldn't say 512 RAM on a PPC mac is the same as 1 GB on an intel mac, but you certainly need more on the intel side to "feel" the same.
  8. TheSpaz thread starter macrumors 604


    Jun 20, 2005
    Hmm... I wonder why that's the case. Maybe since the processors are faster, they're taking bigger chunks of information at once using up more RAM.
  9. TheSpaz thread starter macrumors 604


    Jun 20, 2005
    Where can I look to find information to back up this statement? I'm curios because I've never heard about that before.
  10. coolbits macrumors member

    Nov 1, 2006
    Its logical... why do you want few gigs of ram if it stays there EMPTY ?
    No sense in buying then...
    Best way is that it is used by the system and when apps need it the system frees it for those apps and swaps it to disk or whatever needed.
    active/wired/inactive and free mem is minimum... does that make sense?
  11. thejadedmonkey macrumors 604


    May 28, 2005
    I've often wondered the same thing... I have a mini running 10.3.9 and i've upgraded to 512 megs of RAM, and it runs fine for everything I want it to do, but I've heard that the new macs need minimum 512, and 1 gig is where it's at.. I dunno, but I managed with 256megs for ages. I've definitely gotten the sense that the intel macs require much more ram, but likewise, I can't be defintive.

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