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Does VMFusion release RAM when not in use?
- Thread starter Wheetman
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Same deal with Parallels Desktop 4.0 for Mac as well, only it will also adapt on the fly while running.
When you start the virtual machine, it will allocate the RAM that Windows (or whichever guest OS you have) needs to run, and then give it more and more as you open additional applications.
It does the same thing for CPU usage using the Adaptive Hypervisor option. It's all in order to optimize Mac OS X while running Parallels, instead of taking up unnecessary resources when all you have running in Microsoft is something small like Outlook.
When you start the virtual machine, it will allocate the RAM that Windows (or whichever guest OS you have) needs to run, and then give it more and more as you open additional applications.
It does the same thing for CPU usage using the Adaptive Hypervisor option. It's all in order to optimize Mac OS X while running Parallels, instead of taking up unnecessary resources when all you have running in Microsoft is something small like Outlook.
Mmmm, that's interesting. Do both Parallels and Fusion do this or just Paralells. At the moment I am torn between which system I would choose. A number of the posts I have read suggest that fusion is more stable and doesn't slow the computer down as much as Parallels -any views?
I haven't used Parallels, but I use Fusion regularly. I have an original Macbook Pro, Core Duo 2.0 GHz, 2 GB of RAM, 768 MB allocated to the VM.
My experience is that multitasking within Windows is fine, but trying to multitask between the Mac side and the VM is painful. The absolute worst app for this is Firefox. If I have firefox and Fusion both running, and I've been using Fusion and then switch to Firefox, I generally have a 1-2 minute wait, with a HUGE amount of swapping, while Fusion unloads its RAM to disk and Firefox loads its leaky, bug-ridden self back off the disk and into RAM. Even after that finishes, Firefox is slow. Other apps are slow, and lots of swapping happens, but not as bad as Firefox. It's actually quicker for me to start up Firefox cold in Windows than it is to use an already-running instance on the mac side.
The other thing I've noticed is that the "recovery" of the system once Fusion is done can be quite long. After Fusion has quit, there is still the usual amount of swapping getting anything running. The system is also quite laggy for 10 minutes or more. Sometimes, it never seems to recover completely, and I have to reboot (this is rare).
My experience is that multitasking within Windows is fine, but trying to multitask between the Mac side and the VM is painful. The absolute worst app for this is Firefox. If I have firefox and Fusion both running, and I've been using Fusion and then switch to Firefox, I generally have a 1-2 minute wait, with a HUGE amount of swapping, while Fusion unloads its RAM to disk and Firefox loads its leaky, bug-ridden self back off the disk and into RAM. Even after that finishes, Firefox is slow. Other apps are slow, and lots of swapping happens, but not as bad as Firefox. It's actually quicker for me to start up Firefox cold in Windows than it is to use an already-running instance on the mac side.
The other thing I've noticed is that the "recovery" of the system once Fusion is done can be quite long. After Fusion has quit, there is still the usual amount of swapping getting anything running. The system is also quite laggy for 10 minutes or more. Sometimes, it never seems to recover completely, and I have to reboot (this is rare).
Ouch! Guess this was not what I wanted to hear. Is this with the latest version of Fusion? I had assumed that there would be a a slight decrease in performance, but nothing quite as bad as you have mentioned. Firefox aside, how well does it run with other apps?
To run virtual machines, you should use more RAM.
(Yes I know Core Duo can take only 2gb of ram).
I find there is a big difference between 2gb or 4gb
of installed ram when it comes to virtual machines.
Core Duo 2.0ghz is about 3 year old.
Introduction Date: February 14, 2006
Discontinued Date: October 24, 2006
Current MBP are much faster.
You probably also have a slow (by today standard), 80gb 5400rpm drive. Upgrade your harddrive and it'll run much better.
Info of a computer approaching 3 year old doesn't really say a lot about current, much faster computers.
Good point, I hadn't taken notice of pooky's specs when considering the answer. If I read between the lines; a new Mac whatever, with at least 4GB RAM, shouldn't give me any problems on the virtual machine?
I have a MacBook Pro 2.5GHz with 4GB of RAM, and VMWare Fusion will take anything I can throw at it. swapping between apps is instant.
I like VMWare Fusion a lot better than Parallels. I used to run Parallels, but heard the Unity mode was better than Parallels' equivalent. It's true.
I'm playing with Mac OS X Server, and I have a virtual server computer running, a virtual Windows client running, and my host OS (Leopard) running, with them all connecting to the virtual server. Brilliant!
I like VMWare Fusion a lot better than Parallels. I used to run Parallels, but heard the Unity mode was better than Parallels' equivalent. It's true.
I'm playing with Mac OS X Server, and I have a virtual server computer running, a virtual Windows client running, and my host OS (Leopard) running, with them all connecting to the virtual server. Brilliant!
LeeTom, Thank you for your post. That sounds more like it to me and confirms what others have said that favour Fusion over Parallels. I guess that is my question answered.
Yeah 4GB of RAM should be really smooth.
To answer your second question, Wheetman, the adaptive RAM allocation is unique to Parallels Desktop 4.0 for Mac. It was introduced when version 4.0 launched last November.
As far as stability, I run Parallels Desktop 4.0 for Mac every day, my installation is almost 6 months old, converted from a 3.0 VM, and it's as fast as ever. Granted I do work for Parallels, I like our software better, but there's nothing special about my system (I'm not on an 8 core monster MacPro or anything here) - it's a normal white MacBook, 4GB of RAM, but it's a trooper and runs better than any laptop I've ever had. At any given moment I'm running a half dozen applications (or more) between OS X and Windows and it doesn't flinch.
If you're really looking to compare the programs, I suggest you try out the trials. Nothing is better than seeing these things work first-hand. The Parallels trial has all the features and functionality of the full version, just with a time limit (two weeks) and if you decide to buy it, just enter the full-version key into the trial and you'll be set.
Maybe I will do just that. Can you help me with this question also please. If once I have loaded Parallels and installed Windows, can I run my other Windows apps by installing them on an external hard drive? I don't want to take up more physical hard drive space than I need to on the Operating System machine. Presumably, any apps loaded into the virtual drive still need to take up space on the computers hard drive, even though they are running in a virtual environment?
In the case of a USB external hard drive, yes you can install programs on it to run within Windows. You'll install Windows, plug in the USB drive, and Parallels will ask if you want to connect it for OS X or for Windows (Also managed in the Parallels menu under "Devices"). After that, Windows will see the hard drive exactly the same as it ever would with a physical PC.
The reason I stress USB is because no virtualization software for the Mac supports firewire at this time. You'd have to connect it to Mac OS X and use shared folders to see the data (roughly the equiv. of a network connection).
Yes, I posted my specs for a reason! 
768 is all I can afford to give to the VM while keeping the rest of the system usable. Increasing it makes things much worse.
I did upgrade the hard drive, and it did make a difference, mostly in the duration and extent of the swapping that was occurring.
From the sound of it, maybe it's time for a new laptop...
768 is all I can afford to give to the VM while keeping the rest of the system usable. Increasing it makes things much worse.
I did upgrade the hard drive, and it did make a difference, mostly in the duration and extent of the swapping that was occurring.
From the sound of it, maybe it's time for a new laptop...
I did read on another post that if you reduce the RAM allocation to 512MB it, in some logic defying way, increases the speed. Why not try it and let us know how you get on?Yes, I posted my specs for a reason!
768 is all I can afford to give to the VM while keeping the rest of the system usable. Increasing it makes things much worse.
I did upgrade the hard drive, and it did make a difference, mostly in the duration and extent of the swapping that was occurring.
From the sound of it, maybe it's time for a new laptop...
I like the sound of that. It should read directly from my video camera in that case. Thank you for letting me know.