MAC freezes, when VBOX runs Win7 and Ubuntu simultaneously

[Apotekarnes]

Hello everybody,

my MAC OS X Mountain Lion 10.8 freezes after a few minutes/seconds, when I run Windows 7 and Ubuntu guests in Vbox 4.2.12 (or other versions) at the same time.
If I run only one guest, everything is fine.

What can be a reason for this behaviour?

Regards,
Ralf

[mpack]

Most likely reason is that don't have enough RAM or CPU cores to run the host plus those two other PCs simultaneously on the same hardware.

[Apotekarnes]

Thank you very much! I will try that!