Automatic "Best memory" setting

[Shaddam IV]

I've been playing a lot with the memory I'm assigning to the VM (I'm running Windows 7 on the VM, 3D enabled). Through intense trial and error sessions I've found 816 MB / Optimize for the VM to lead to very satisfying results on my 2 GB MBAir (NVidia 9400) for running Mac and Windows programs concurrently. Even adding just 16 MB to the VM for a total of 832 MB causes slowdowns due to virtual memory file thrashing. To avoid thrashing with 832 MB I'll have to optimize for OS X which slows some Windows functions down (e.g. shutdown after lengthy work sessions in Windows). Running the VM with 1024 MB has no real speed benefits but really slows things down once I start an application on the Mac.

I suggest that a future version of Parallels makes a prediction of what memory setting is optimal for the VM. It could base this recommendation on the Guest OS, the virtual graphics card / 3D acceleration settings, the Mac's total physical memory, and the Mac's current free memory. The user should be able to override this recommendation, of course - but you could indicate that recommendation in the memory dialog.

 

[dev@parallels.com]

default

Shaddam,

By default PD5 suggests 768Mb for W7 VM on 2GB boxes. Have you copied this VM from other machine or it's from previous PD4 installation or a brand new created in PD5?
How much VM RAM PD5 suggest for newly created W7 VM in your case?

 

[Shaddam IV]

Hi dev,

I bought PD 5 and replaced PD 4 on my machine (where I had been running a Windows 7 beta VM, and a Windows XP VM). I then created a brand-new Windows 7 VM in PD 5. As far as I recall, PD 5 recommended 1,024 MB for the VM during creation, but that's a few months ago (when PD 5 came out). I haven't recently created a new VM but can certainly try once I'm back from my holidays.

My personal recommendation would be more than 768 MB to run Windows 7 including all the UI options (Aero etc) but that's of course just my personal impression. My main (and surely quite unscientific) "benchmark" is the speed of Windows and MS Office after I've used a resource-intensive game such as The Battle for Middle Earth.

Thanks for picking this up!

 

[Shaddam IV]

I created a new Windows 7 VM yesterday on my 1.6 GHz 2 GB MBAir, and Parallels indeed suggested 768 MB of Ram. Now, would it also suggest 768 MB on a 8 Gig Quadcore Mac?

 

[dev@parallels.com]

I created a new Windows 7 VM yesterday on my 1.6 GHz 2 GB MBAir, and Parallels indeed suggested 768 MB of Ram. Now, would it also suggest 768 MB on a 8 Gig Quadcore Mac?

No, on machines with >2GB RAM PD5 suggests 1Gb for W7 by default. We consider to increase default VM RAM up to 2GB for >=8Gb boxes in the future.