• Register
  • Help
Results 1 to 9 of 9

Topic: Where is this RAM gone?????

Share/Bookmark
  1. #1

    Where is this RAM gone?????

    Strange observation concerning memory and CPU load

    As a Logic6.3.3 user who did experience some problems I did consider changing over to Cubase SX and did start to learn this sequencer. By doing this I did the following observations:

    1. My Dual G4 1.25 GHz / 2 GB RAM does has 1, 74 GB free RAM after starting up OS X Panther.
    2. A: After starting Logic with 8 empty Instances of GPO Kontakt there is 1.53 GB free RAM
    3. B: CPU load is between 4 and 12%
    4. C: After loading VL solo 2 Strad (dry) free RAM is 1.46 GB
    5. D : While playing the violin CPU load is between 16 and 27%
    6. E: After unloading the VL patch free memory is 1.48 compared to 1.53 with the same situation before????
    7. Now I load some patches in all 8 GPO instances until remaining 422 Mb RAM and I remove all in order to obtain the same scenario as 2. A: BUT there is only 1,009 GB free RAM instead of the 1, 53 I had after starting up Logic.

    Where is this RAM gone????? [img]images/icons/mad.gif[/img]

    And now even more surprising the same experience with Cubase SX

    1. My Dual G4 1.25 GHz / 2 GB RAM does has 1,74 GB free RAM after starting up OS X Panther
    2. A: After starting Cubase SX with 8 empty Instances of GPO Kontakt there is 1.42 GB free RAM
    3. B: CPU load is between 24 and 38% ( [img]images/icons/confused.gif[/img]
    4. C: After loading VL solo 2 Strad (dry) free RAM is 1.40 GB
    5. D: While playing the violin CPU load is between 39 and 54% (!!!!) [img]images/icons/confused.gif[/img] [img]images/icons/confused.gif[/img] (16 and 27% in Logic)
    6. E: After unloading the VL patch free memory is 1.41 compared to 1.40 with the same situation before????
    7. Now I load some patches in all 8 GPO instances until remaining 261MB RAM and I remove all in order to obtain the same scenario as 2. A: BUT there is only 954 GB free RAM instead of the 1, 42 I had after starting up Cubase SX.

    Where is this RAM gone????? [img]images/icons/mad.gif[/img]

    Logic is obviously more efficient but it has a price: If you load and unload patches RAM reserves will be going smaller and smaller, -without loading more sounds. Finally Logic will “Unexpectedly quit”. Since it does not have an auto save function……..

  2. #2

    Re: Where is this RAM gone?????

    This is memory leakage. An app calls for new RAM, and doesn\'t release it when it\'s done. Not an uncommon problem.

    A reboot will reclaim it :-)

    Trond

  3. #3

    Re: Where is this RAM gone?????

    Try to reload the instrument, the OS should see that there are data in memory not used and should free them.
    Until it doesn\'t have \"requests\" of RAM space probably it takes for a certain time the \"spaces\" occupied. It depends on the algorythm of memory update implemented.
    If it doesn\'t free the memory, ok now there is a \"real\" problem.
    Michael

  4. #4

    Re: Where is this RAM gone?????

    Originally posted by IGOR:
    Strange observation concerning memory and CPU load
    ...
    2. A: After starting Logic with 8 empty Instances of GPO Kontakt there is 1.53 GB free RAM
    ...
    7. ... and I remove all in order to obtain the same scenario as 2. A: BUT there is only 1,009 GB free RAM instead of the 1, 53 I had after starting up Logic.

    Where is this RAM gone????? [img]images/icons/mad.gif[/img]

    ... Finally Logic will “Unexpectedly quit”...
    <font size=\"2\" face=\"Verdana, Arial\">Your observations about memory usage do not necessarily indicate a problem, unless as you say your program unexpectedly quits. I assume you mean that you believe that memory management has corrupted your program and it crashes.

    I was concerned to see if I could detect a problem on my computer, so I ran a load/unload test. I use Cubasis, Windows XP Home, 760 MB Ram. I repeatedly loaded and unloaded various instruments and multis. I monitored the available memory and noted that the available memory following the first 10 unloads was decreasing, but after about 20 unloads the available memory was back to the amount of available memory following my first unload. This is a feature of how the software sets aside memory rather than returning it to the operating system. I don\'t think you need to be concerned about following it as closely as you do.

    But, if your software does indeed crash after doing this, then, of course, there is a problem. But just seeing a change in the available memory by itself does not indicate a problem.

  5. #5

    Re: Where is this RAM gone?????

    I think the memory problem has something to do with the player not deallocating the shared memory when if it done using a sound.

    My guess is that the NI player loads the sounds into a chunk of shared memory so that all instances of the player have access to the sounds without the need to use additional by loading the sound into it\'s own space.

    It is the job of the last player open to deallocate the shared memory when it exits, if the players are sharing sounds (resources) it might be that they forget to keep track of which one is use what sound.

    So if two players use the same resource and one is switched to another resource (sound) then the other is switched to another sound the second player might think that the first sound is still in use because the first player is still running and the link count on the shared memory is the same and as such the unused sound remains in the shared memory.

    Just a thought,

    Aaron

  6. #6

    Re: Where is this RAM gone?????

    I\'d guess it\'s related to bad memory management by either the sequencer program, plugin, or the OS. It\'w quite prominent with most OSes, where you get memory \"leaks\" or \"stuck\" memory after loading and unloading memoring hogging programs.

  7. #7

    Re: Where is this RAM gone?????

    I was concerned to see if I could detect a problem on my computer, so I ran a load/unload test. I use Cubasis, Windows XP Home, 760 MB Ram. I repeatedly loaded and unloaded various instruments and multis. I monitored the available memory and noted that the available memory following the first 10 unloads was decreasing, but after about 20 unloads the available memory was back to the amount of available memory following my first unload. This is a feature of how the software sets aside memory rather than returning it to the operating system. I don\'t think you need to be concerned about following it as closely as you do.
    <font size=\"2\" face=\"Verdana, Arial\">Thanks for all the valuable feedback!

    The quote above mentions a Windows machine, I did also some tests on Window XP home with 1GB RAM on board. The kind of problem which do appear while using Kontakt on the Mac do never appear on this plattform. I do experience at least 5-10 crashes per day using Logic on the Mac and never had a single one on the PC running Windows XP with Cubase SX......I am not hired by Microsoft....I am an old Mac user (back to 1987) and I am sad about all this problems which are now happen [img]images/icons/frown.gif[/img]

  8. #8

    Re: Where is this RAM gone?????

    Just General info on how OSX/unix works with Ram.

    Wired ram: ram used by the mach kernel that cannot be paged out.

    Active Ram: ram currently/actively being used

    Inactive Ram: ram \"previously\" used but no longer actively used..which can be reclaimed as needed based on load. Unix keeps the old previously used memory mapped in case you reopen the program..etc..to make it open faster. But, the ram is sitting idle and can be reclaimed. This can grow to a very large number, but it is still available ram..as needed.

    Free Ram: is ram that has not been mapped or used nor actively being used.

    The total ram that is actively being used by OSX (or a unix based OS) is wired ram..plus active ram. That\'s it. Everything else is available.

    OSX uses 128 megs on startup (wired ram plus active ram). Hence, the sys requirement for running it.

    OSX measures \"used ram\" as wired plus active \"plus\" inactive.

    What I don\'t know, is whether the process for reclaiming inactive ram is more a function of the OS or the app/priority that is running. I would imagine it\'s both.

    What I\'m saying is...these ram numbers are working the way they should in a unix based OS. And that reading \"inactive ram\" as part of your used ram for any given point in time..is not an accurate reading of the total ram being actively used...(it\'s still available ram...as needed..and can be reclaimed). It\'s not a mem leak that I know of..to see inactive ram numbers continually rise. The more things you open..and then not use..the more inactive ram numbers you will have. You can see this yourself...by rebooting OSX. Open the terminal window..and run \"top\". You\'ll see that wired plus active equals right at 128megs of ram. But, there also a small amount of inactive ram measured there as well. This is ram used during startup process..but..then..not actively used after startup. Could be libs loading..etc. (not sure). The more apps you open..the more active and inactive ram grows. When you quit an app..it \"releases\" the ram as far as being \"active\"...and labels it \"inactive/ie..available\".

    This operation of reclaiming ram..is not a \"paging\" VM type operation. If you note in \"top\"..your active pages in and out are listed..and they will be \"zero\". Run your app..with top open..and see if you note any paging operations. What I\'m not sure of..is why audio apps are having such a problem with this. I suspect..it\'s becuse of critical timing issues in the flow of data in and out of things. But, don\'t know for sure. I\'m also not sure..if this is a timing issue..if it\'s something that needs to be addressed on the OS side..or the apps side or both. As far as I know..OSX manages such mem operations based on priority as needed. If there are timing issues with this for audio type applications..then it would be up to apple to address this I would think. (again..not sure). But, the memory activity..of OSX is working just as it should be..in so far as the behavior you describe. I hope that helps some ..at least in so far as a general understanding.

  9. #9

    Re: Where is this RAM gone?????

    Just to clarify, if you are reading your ram usage from OSX \"used ram\"...it can be misleading..because it includes \"inactive\" ram...which is still available. IT releases the ram by labeling it..from active..to inactive. But, it does not \"flush\" this out to turn it into \"free ram\"...nor does it need to..as it\'s still available.

    The advantage to this..is that should you need those operations again..they are alredy mapped and can be quickly shifted to active status and it cuts down on the flushing, etc..operations that most OSs go thru continously. (and in mem errors from such operations). It only \"flushes\" when it needs it. Not until.
    And this operation..is an \"overwrite\"..not a paging operation...as observed in top. That\'s my understanding at this point.

Go Back to forum

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •