[mirko]

Hi,

Any thoughts/opinions on OF performance when running on vmware linux vs. linux installed directly on the machine.

I'd prefer the convenience of having both windows and linux running at the same time, but I don't want too much of a performance hit.

Thanks,

Mirko

[wyldckat]

Hi Mirko,

My experience with various Ubuntu's with VMPlayer has been very productive. Linux OS'es can do some serious number crunching, compiling and building applications, as well as power computing, even when inside a virtual machine!
So far it still has been kicking Windows'es where it hurts, when comparing running tutorials inside the VM in single and multi-core (4 max) versus running a cross-compiled version of OpenFOAM for Windows with MinGW (not Cygwin)! I don't have official timings with the VMs, but the overall experience is still in favour of Linux.

Furthermore, my experience has been that 32bit VM machines seem to run better than 64bit VMs, even when using a 64bit OS in the real 64bit machine. This might not be an issue if the CPU already has VT stuff, which hasn't been the case in most of my experiments.

Either way, choosing which OS will be VM'ed will depend on which OS you'll be using the most. Keep in mind that with a VM, your real system will be sharing memory between both machines and running CFD can be rather memory hungry! And if the VM needs to hit the swap, then it's going to be messy... as in reaaaally slow!

Best regards,
Bruno

[mirko]

Originally Posted by wyldckat

Hi Mirko,

My experience with various Ubuntu's with VMPlayer has been very productive. Linux OS'es can do some serious number crunching, compiling and building applications, as well as power computing, even when inside a virtual machine!
So far it still has been kicking Windows'es where it hurts, when comparing running tutorials inside the VM in single and multi-core (4 max) versus running a cross-compiled version of OpenFOAM for Windows with MinGW (not Cygwin)! I don't have official timings with the VMs, but the overall experience is still in favour of Linux.

Furthermore, my experience has been that 32bit VM machines seem to run better than 64bit VMs, even when using a 64bit OS in the real 64bit machine. This might not be an issue if the CPU already has VT stuff, which hasn't been the case in most of my experiments.

Either way, choosing which OS will be VM'ed will depend on which OS you'll be using the most. Keep in mind that with a VM, your real system will be sharing memory between both machines and running CFD can be rather memory hungry! And if the VM needs to hit the swap, then it's going to be messy... as in reaaaally slow!

Best regards,
Bruno

Thanks Bruno :-)

[alberto]

Hint: activate VT if your CPU has it (many vendors disable it, especially on laptops), but virtualize a 32bit system. It requires less memory than the corresponding 64 bit system, and performance will be a bit better.

Best,