CPU and memory high end 3D CAD in Parallels

Discussion in 'MacBook Pro' started by mudmanmike, Jul 22, 2009.

  1. mudmanmike macrumors newbie

    Aug 10, 2008
    Hello every one,

    I am asking that question that so many are asking. I come here because I always get good advise here!

    I am a recent Mac convert and will never buy another PC. Unfortunately I am using some high end CAD software that is only available for Win XP. I run it in Parallels because I like the convience. I have had my MBP 2.5Ghz, 4GB RAM for a year now and am ready to replace it. I figure that the 2.8 Ghz processor will give me some performance upgrades. Plus my batteries (I have two) are starting to loose run time.

    My questions are..... Do yall think I could use the extra power of the 3.06 processor or is the 2.08 just as fast?

    Secondly, Would I benefit from 8GB of memory?

    I am including a screen shot of my machine running the CAD program after a rendering and some scene rotating. You can see the processor is pegged. The memory never seems to max out... But I really dont understand the virtual vs. physical memory stuff. If I have 8GB of RAM I guess I cold assign 4GB to the Virtual machine. It seems like that would help speed it up... Maybe the system would not rely so much on the Mac's virtual memory. There seems to be a lot of unused memory though, I really dont understand this stuff.

    Also this was not a big job and I was not running any other programs like Iphoto, PhotoShop or a spreadsheet at the same time. If I am running a big job it really starts to slow down, not just the 3D graphics stuff but the database calculations for job reports as well.

    I can give yall more info if you need.

    Thanks as always,


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  2. KoolStar macrumors demi-god


    Oct 16, 2006
    Well, the speed increase form 2.8 to 3.06 is not going to make too much difference. If you run in parallels, ram will be the key factor. If you were to upgrade it to 8GB you would need to run x64 windows to take the advantage of the ram that is provided over the 3.2 max of 32bit.
  3. MacMini2009 macrumors 68000


    May 22, 2009
    If you have the money for the 3.06GHz processor, get it. 4GB is fine for now. 8GB is too expensive at the moment so get 8GB in the future. If you want more performance, get a SSD.
  4. mudmanmike thread starter macrumors newbie

    Aug 10, 2008
    Here is another screen shot showing a larger job... But they still get bigger than this. At this size of job simple clicking on various tools or functions gets slow. I would say a 3 to 5 second wait for the action.

    I guess I can increase the Virtual Machine's memory another GB But I already have 3GB to the VM, so I dont think Parallels will take any more from the OS. I think that is why it uses so much virtual memory.

    What ever.... I really dont know what I am talking about. I just dont want to use BootCamp. I spend a lot of time on this CAD program but I refuse to give up my Apple software. I like to multitask using both OSes.

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  5. mudmanmike thread starter macrumors newbie

    Aug 10, 2008
    OK. I know about the 64 bit version of XP but I dont really understand the technical difference. Does the CAD program have to be 64bit compatible? Or is it just an OS thing?

    I just read about XP 64 on Wikipedia. It confirmed the 3.2GB limit for windows programs in XP 32GB. I think RAM is the issue also. It seems that the processor is not really pegged the whole time, only during renderings for the 10 seconds it takes to make one. But it is the slow response of the rest of the program that is a problem. It seems odd that the Mac system profiler still shows nearly a GB free. I do not understand that.

  6. rgarjr macrumors 603


    Apr 2, 2009
    Southern California
    U should run that 3D software on BootCamp, you will get better results.
  7. iLog.Genius macrumors 601


    Feb 24, 2009
    Toronto, Ontario
    Agreed. If you run in a native environment, you will get much better results. Usually not a good idea to run intensive apps through virtualization.
  8. jtus macrumors member

    Jul 12, 2007
    I also have to use autocad on my MBP it does work fine running it wirh Parallels but if you need to run Autodesk Inventor 2010 it will not run with Parallels and you must use Bootcamp.
    Autocad does run beter with Bootcamp but you won't see much difference between the 2.8 or 3.06 cpu's.
  9. jdechko macrumors 68040

    Jul 1, 2004
    You aren't even close to maxing out your RAM in either of those screenshots. You still have ~1GB free in both of them, and you're not excessively paging out either.

    And without some tweaking, Windows will only assign ~1GB RAM to a given process. You can bump it up to about ~2GB but it's not going to help much given the fact that you're still in a virtual environment.

    (I learned this when I was doing some renderings in 3ds/viz)

    I'd still vote for bootcamp, 2.8/4GB for your new machine (if you need a new machine, that is)
  10. geoffreak macrumors 68020


    Feb 8, 2008
    Sound advice. You will really only find that the 3.06GHz helps in tasks which bring your CPU up to 100% for long periods of time, but even then only slightly. It is a luxury, but if you can afford it, go for it.

    When working with a virtual machine, the entire 32bit/64bit argument is irrelevant. The VM won't be able to use all your memory anyways. Just use whatever version of XP is compatible with your program, but be warned that 64bit XP can't run programs which are 32bit (such as iTunes).
    Running under BootCamp, you would benefit more from 64bit.


    I think this may be the case in 32bit XP, but I don't think that there is such a limitation in 64bit XP or Vista.
    This doesn't change the fact that 4GB is enough RAM for your use.
  11. jdechko macrumors 68040

    Jul 1, 2004
    For an explanation of memory management in OS X, check out this link: http://www.macosxhints.com/article.php?story=20010613140025184

    The reason why I think you've got so much free memory is that XP isn't using all that you are allocating to it. How much memory does the Task Manager in XP show, since that's the memory management that we need to look at? Can you post a screenshot of it for us, Mike?

    geoffreak, according to Microsoft, it affects both XP and Vista, but only in the 32-bit flavors. This link is similar to what I went through, configuring the /userva=XX switch in Windows to allocate more memory to the application space.

  12. geoffreak macrumors 68020


    Feb 8, 2008
    Ah. Good to know. Still a silly limitation.
  13. mudmanmike thread starter macrumors newbie

    Aug 10, 2008
    Thank you everyone,

    I will just respond to all the comments and suggestions at once.

    I included the screen shot of the windows memory usage.

    I run Inventor (AutoDesk 3D solid modeling program) as well, it is nothing compared the the program I am showing you. The complexity inside these models is staggering because it is a full CAD/CAM engineering solution. Not just pretty pictures. This is a parametric database driven CAD model not a solid model like in Inventor or Solid Works. Although technically solid modeling uses more computer resources, this program is doing a lot more behind the scenes with material lists, pricing, optimizing and referencing databases of catalogs and materials. Blaa blaa blaa.

    First of all it sounds like yall are saying that running in a VM is more of a handicap than I thought it was. Do yall mean that I really cant get acceptable performance in the VM even with more memory and power? There must be some constraints I do not understand.

    It was mentioned that there is 1GB of memory unused in the Mac memory. This confuses me because the CAD program is running like it is low on memory. It is as if Parallels is not trying to use that last GB of RAM even though I set up the VM to use 3GB. That is why I am wondering if more memory will help. Or is this slow running not a sign of lack of memory or processing power but just an inherent limitation of the VM? By the way, the problem is not in the graphics... if it is a large job the program runs slow even when there are no 3D graphics on the screen, like when running production reports and material optimizations. Basically the whole damn thing gets slow.

    I am still confused about the 64 bit thing. Would I benefit from getting the 64 bit XP package or is it just more work for the machine? It looks like the CAD program I am using is a 32 Bit program. Does this mean I wold not see any benefit in running the 64 Bit version of XP?

    I spend hours using this CAD program, so I would miss the Mac programs (Mail, Safari, Pages, Numbers, Iphoto) if I was running in Boot Camp. I ONLY use the XP environment for two programs in hopes that it will stay clean and fast. I know there is a way that Parallels can run a windows partition on the Mac drive (a Boot Camp partition) in the VM giving me the option of using Boot Camp or the VM depending on which is more convenient at the time. For example, I would use Boot Camp to work on large jobs and the VM when multi tasking is more importaint. What is your experience with this kind of installation?

    Finally do you VM/BootCamp CAD guys have any secrets for optimizing the XP installation? Remember I only use it for these two CAD programs; no internet, games, email, photos, virus protection... nothing else.

    When I get my new machine I will reinstall XP as per your recommendations.

    Thanks again everyone,


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  14. jdechko macrumors 68040

    Jul 1, 2004
    I completely forgot about the fact that you are running a full 3D program in an experimental 3D environment. Parallels and Fusion 3D performance is nowhere near what you could get if you were running Inventor in a native environment.

    From the looks of your Windows Task manager, you're only using about 250MB of RAM in Windows. What does the processes tab show?

    So don't worry about the RAM, don't worry about 64-bit, do reinstall XP via Bootcamp (and then you can link it to VMWare/Parallels. If you are really concerned about space, you can try to create a minimal installation of XP using some free tools like nLite.

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