Multiple-CPU Support

[AkashA]

I have a general question about how Parallels Desktop 5.0 handles multiple CPUs. I'm running engineering software that is very CPU intensive and will exploit up to 16 CPUs if they are available on the machine. When configuring a virtual machine, the Parallels user manual states "Parallels Desktop automatically calculates the maximum allowable number of virtual CPUs based on the number of physical CPUs available...".

On a dual core Macbook Pro I am working with, Parallels gives 1 CPU to the virtual Windows 7 machine I have set up. My question concerns how many CPUs Parallels reserves for the host OS. Is 1 CPU always reserved for the host OS, or does parallels split the CPUs evenly among the Host and Virtual Machines? For example, if I have an 8 CPU machine, will Parallels configure the virtual machine with 7 CPUs (leaving 1 for the Host OS), will it give 4 CPUs to the Virtual machine (leaving 4 for the Host), or will it split them some other way?

Also, as far as I'm aware, a single virtual machine can have a maximum of 8 CPUs, is this correct?

Thanks for your input!

 

[Elric]

I have a general question about how Parallels Desktop 5.0 handles multiple CPUs. I'm running engineering software that is very CPU intensive and will exploit up to 16 CPUs if they are available on the machine. When configuring a virtual machine, the Parallels user manual states "Parallels Desktop automatically calculates the maximum allowable number of virtual CPUs based on the number of physical CPUs available...".

On a dual core Macbook Pro I am working with, Parallels gives 1 CPU to the virtual Windows 7 machine I have set up. My question concerns how many CPUs Parallels reserves for the host OS. Is 1 CPU always reserved for the host OS, or does parallels split the CPUs evenly among the Host and Virtual Machines? For example, if I have an 8 CPU machine, will Parallels configure the virtual machine with 7 CPUs (leaving 1 for the Host OS), will it give 4 CPUs to the Virtual machine (leaving 4 for the Host), or will it split them some other way?

Also, as far as I'm aware, a single virtual machine can have a maximum of 8 CPUs, is this correct?

Thanks for your input!

Hi,
No, parallels doesn't binds to particular CPUs. If Parallels is idle, all CPUs are available to Mac OS X (and vice-versa).

Actually, balancing CPUs between Mac's application and Parallels Desktop is a job of Mac OS X. Parallels doesn't grab anything. It is event possible to start some intensive application on Mac OS and intensive application (that will use 100% CPU) in Parallels and both should work well (but of course in 50% of power)

About maximum CPUs - I can't remember... there should be a notice in the documentation. But this number may not be more then the number CPUs on Mac