>>>>> On Wed, 12 Dec 2012 12:43:36 +1100, Peter Jeremy said: > > [Please copy me in any replies] > > My VPS provider will not offer 32-bit FreeBSD guests because they use > excessive (ESXi) host CPU time. I have done some experiments using > VirtualBox on my FreeBSD/amd64 8-stable host and see the same. > > An idle 32-bit FreeBSD 9 or 10 guest uses very roughly 25% more host > CPU than an equivalent 64-bit guest. An idle 32-bit FreeBSD 8 guest > uses very roughly 50% more host CPU than an equivalent 64-bit guest. > > This problem does not show up with Linux or Windows7 but occurs with > both VirtualBox on AMD and ESXi on Intel CPUs. > > Since the problem shows up with different virtualisation environments > and on different CPUs, this suggests this is a FreeBSD guest issue. > My suspicion is that the cost of handling an interrupt on FreeBSD/i386 > is higher than the cost on amd64 - and this is more obvious on 8.x > because it doesn't use dynamic ticks. > > Has anyone else seen this behaviour and does anyone have any suggestions > for improving the FreeBSD/i386 performance.
I can't repeat that with idle FreeBSD 8.0 guests running in VirtualBox 4.1.18 on Linux kernel 2.6.35.14-106.fc14.x86_64. In fact, the 64-bit one uses 4.8% of the CPU whereas the 32-bit one uses 4.2% (according to ps "bsdtime" measured over 1000 seconds). What absolute percentages are you seeing? __Martin _______________________________________________ freebsd-emulation@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-emulation To unsubscribe, send any mail to "freebsd-emulation-unsubscr...@freebsd.org"
