Allocating more than 8GB to a VM in Fusion 4 over Lion?

[martur]

I was wondering if anyone ever succeeded in allocating more than 8GB to a VM (guest Windows 7 64bit) running on Fusion 4 over Mac OS X Lion?

I have this VM running Windows 7 than is running low on memory at 6.5GB on my Macbook Pro (8GB of physical memory).

I'm considering upgrading my Macbook Pro to a more recent model to me able to have 16GB of physical memory with OWC upgrade to be able to provide my Windows 7 guest with some thing like 10GB or 12GB.

I just want to make sure it is even possible.

Thanks,

MT

[WoodyZ]

You cannot assign more the 8GB of RAM to a Virtual Machine under VMware Fusion's GUI however you can manually edit the memsize = parameters value in the .vmx configuration file.

However that said, the latest Mac Book Pro's only support 8 GB RAM max and this is the official published limit and also what the motherboard will take per conversations with several knowledgeable employees at the Apple Store.  Additionally if you order the MacBook Pro with an SSD there is no guarantee that it will be an OWC SSD as Apple uses SSD's from several different manufactures.  Also from what I've seen there is considerable differences between the SSD's used, which is why I would not order one directly from Apple considering the price for the 512 GB SSD at $1,100 USD, and will not allow the user to specify which manufactures SSD to be installed.

[martur]

Thanks WoodyZ for the quick reply.

While I know that published limits of the MBP is 8GB, in reality it can be upgraded to 16GB (2 x 8GB) dependign on which version of MBP.

My current MBP (17in Unibody from early 2009) has a published limit of 4GB (2 x 2GB), and yet I have been running 8GB (2 x 4GB)for about 2 years.

The latest MBP has a published limit of 8GB but can easily be expanded to 16GB. OWC is just one vendor (there are others) that offers upgrades for MBP beyond the *published* limits and that actually work fine.

(http://eshop.macsales.com/shop/memory/Apple_MacBook_MacBook_Pro/Upgrade/DDR3_1333MHz_SDRAM).

As for the SSD, I have also upgraded my current MBP to have a 250GB SSD, and a second 500GB hard drive in the DVD drive bay (I removed my DVD drive and only plug it externally when needed).

Now, *IF* I do modify the memsize= parameter to say 12GB in the .vmx configuration file, will Fusion really accept to actually allocate the 12GB to my VM. I know that Windows 7 64bit will use 12GB, but I'm just not sure Fusion will actually do it.

Perhaps someone with 16GB physical memory on say a Mac Pro can confirm, for having done this.

Thanks,

MT

[WoodyZ]

Now, *IF* I do modify the memsize= parameter to say 12GB in the .vmx configuration file, will Fusion really accept to actually allocate the 12GB to my VM. I know that Windows 7 64bit will use 12GB, but I'm just not sure Fusion will actually do it.

While the GUI RAM Settings in VMware Fusion 4 will only go to 8 GB it will accept greater values when manually edited.  This of course assumes you actually have more then the amount you're manually assigning.  In other words since you only have 8 GB Physical RAM you cannot assign 12 GB manually and expect it to work.  Now with 16 GB you can assign 12 GB manually.

Have a look at: Re: Does vmware fusion 4 support > 8Gb RAM?

[WoodyZ]

While I know that published limits of the MBP is 8GB, in reality it can be upgraded to 16GB (2 x 8GB) dependign on which version of MBP.

When I last checked, a few months ago, I was told it would not support 16 GB nor would they install the RAM if I brought it in.  Also I'm not about to open a brand new +$3000~$4000 USD notebook that is under warranty just to experiment upgrading if I'm told the motherboard will not support it and is why I've yet to purchase a new one and will wait for officially supporting 16 GB in a MackBook Pro before purchasing a new one.  I did not open my current MacBook Pro to up the RAM and HDD until it was out of warranty.

[joemath]

martur,

I bought a new MBP earlier this month.  I installed 16GB RAM and a 512GB SSD (both from Crucial). 

My understanding is that RAM and SSD upgrades (in the hard disk bay) do not void AppleCare on a MBP.  I do recommend that you use the Lion Recovery Disk Assistant (http://support.apple.com/kb/dl1433) to create a recovery partition on the SSD because AppleCare support may need it in order to troubleshoot hardware issues.

Per the instructions from WoodyZ, I was able to allocate 12GB of RAM to a Win7 x64 VM.  My Windows Experience Index subscores with one processor allocated are Processor = 5.6, Memory = 7.9, Graphics = 6.0, Gaming Graphics = 6.0, and Primary Hard Disk = 7.9.  With two processors allocated, Processor = 6.9 and the others subscores are unchanged.

When the VM starts, I do get a warning from Fusion:  "This virtual machine is configured with an unsupported main memory size, 12288 MB.  VMware Fusion supports a maximum main memory size of 8192 MB. Continuing may result in poor perfomance."  You can check the "never show this dialog again" box to permanently skip the warning.

I had the same questions as you before I ordered the new MBP, so hopefully you find this info helpful.

--Joe

[ColoradoMarmot]

Yep, RAM and Disks are user replacable parts, and the 2011 MBP's work just fine with both the SSD and 16GB of RAM.  TRIM support is not required with many modern SSD's as they have built-in garbage collection that's much more efficient.

Keep in mind that using the recovery assistant will wipe the entire disk, so do it before cloning.  In the end, I just did a clean Lion install and used the migration wizard to move everything over (the lion wizard is MUCH better than SL was).

[martur]

Thanks Joe! Very useful information. Much appreciated.

MT

[martur]

Thanks dlhotka. Also good to know and appreciated.

[martur]

Joe,

I forgot to ask you about performance when using more than 8GB of memory the GUI allows you to configure...

I'm not entirely sure how to ask this...

If you configured say 12GB, which would leave 4GB of physical memory for Lion and other system processes, did you feel that the performance of your guest machine was reflecting the allocated memory?

Or did you feel the performance degrades to the extent of making questionable any memory gain in the guest?

Thanks,

MT

[joemath]

MT,

I typically run multiple smaller VMs with a combined footprint of 8GB.  I bought the new MBP so I could run them simultaneously (which was impossible on my previous MBP).

I created the 12GB VM because you asked about it and I was curious myself.  It's a little difficult to judge performance since I don't normally use that configuration.

That said, I did run a test for you.  I found an app called MemAlloc (http://www.soft.tahionic.com/download-memalloc/index.html) that grabs chunks of RAM.  It's a 32-bit app and cannot see beyond 4GB, but running three instances of it, I grabbed at total of 10GB of RAM.  Add in the overhead of Win7 x64, and the Physical RAM as reported by Windows Task Manager was Total=12287, Cached=40, Available=40, Free=2.

Everything behaved well at that point.  In the VM, I was able to surf with IE, launch other apps, etc without problem.  There was a slight bit of hesitation in the UI - just enough to notice, but not enough to affect usability.  It was probably due to paging given that RAM was maxed out.  On the host, there was no indication of memory constraints.  Safari, Mail, iTunes and more were all performing normally in the remaining 4GB.  Fusion didn't flinch either.

The main caveat with my test is that the VM used almost no CPU.  If your VM needs a full 12GB plus significant CPU cycles, then you might have a different experience.

But for my test, everything worked well. I only tinkered with it for a few minutes, but this type of RAM-intensive arrangement seemed very usable.

I hope this helps.

--Joe

[3DLake]

I'd also like to point out that manually editing the .vmx file to allocate larger amounts of RAM also appears to work just fine with VMware Fusion V3.1.3 and Snow Leopard 10.6.8.

I have an eight core Mac Pro (2009) with 96GB of RAM that I use for Sharepoint development.  I have two flavors of Windows server 2008, one SBS (Small Business Server) 2011 and a Windows 7 system and they all play well together on the same system.

All of my Windows server systems are set to:  memsize = "16384" and two or four CPUs.