On 4 March 2014 11:28, Matt Wheeler <m...@funkyhat.org> wrote: > Actually the way this works is using the proper hardware > virtualisation capabilities of the CPU, so the performance will be the > same as running on a 64bit host OS. It's not possible to run a 64bit > guest on a host system without VT-x or AMD-V (even if the host OS is > 64bit)
I would expect it to use hardware virtualisation, yes, and that works fine on 32-bit host OSes. But surely a task on 32-bit host Windows or Linux can't execute 64-bit code, because the CPU isn't in Long Mode? And even with PAE, a 32-bit host OS has 4GiB of virtual address space, typically split 2:2 or 1:3 between kernel and app space, so a single 32-bit app can't have more than 2GiB or possibly 3GiB of process space. So your fancy 64-bit guest OS only gets 2GB or 3GB of contiguous address space, surely? In which case, what's the point of having a 64-bit guest? Mac OS X is a bit different and 32-bit kernels *can* execute 64-bit processes. AFAIAA Linux and Windows can't. I welcome correction, though. -- Liam Proven * Profile: http://lproven.livejournal.com/profile Email: lpro...@cix.co.uk * GMail/G+/Twitter/Flickr/Facebook: lproven MSN: lpro...@hotmail.com * Skype/AIM/Yahoo/LinkedIn: liamproven Tel: +44 20-8685-0498 * Cell: +44 7939-087884 -- ubuntu-uk@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-uk https://wiki.ubuntu.com/UKTeam/
