Ah. I see "32-bit host operating systems". Here's the quote from the VirtualBox manual:
In particular, 64-bit guests are supported under the following conditions:
1. You need a 64-bit processor with hardware virtualization support (see chapter
1.2, Software vs. hardware virtualization (VT-x and AMD-V), page 11).
That's an artificial limitation, too. Sun proved you can run 64bit operating systems and virtual machines on 32bit CPUs.
Huh? Since when did Sun prove this?
Obviously it's slower, though, since 64bit operating systems assume the existence of some speed-enhancing CPU features.
You mean like the existence of a 64-bit CPU?
UNIX enhancements aren't.