virtualbox 4.2.4 tooooo slow

[진석오]

Dear,

I installed virtualbox 4.2.4(CFT) on zfs FreeBSD 9.1-RC3

installing and windows guest(windows 8) install with guest addition was
successful.
but the windows guest is too slow, it is hardly usable.

my hardware specs.
intel i7 quad core 3.6. ghz, with 8 thread
mem 16G
motherboard - asrock z79 extreme 6.
intel SSD 120G.


my virtualbox vdi file is at zroot/bigfile, with
primaryache, secondarycache = NONE, even sync=disabled because of slow
performance.

virtual machine settings
- mem  4096M, cpu 4ea
- 25g vdi(SATA controller) with SSD ticked
- VT-x/AMD-V, Nested Paging
- video 128M



I tried the VB on UFS because ZFS was too slow, but the result was the
same..
I downgraded to FreeBSD 9.0 on UFS or / ZFS, but but the result was the
same..
and  I tried virtualbox 4.1.22 on FB 9.0/9.1-RC3,but but the result was the
same..

but sad story is that
I found that virtualbox 4.2.4 on linux(opensuse 12.2, ext4) was very fast.
opensuse is installed on the second harddisk(NOT SSD)  at the same computer.

virtualbox zfs/FreeBSD on SSD is much slower than virtualbox ext4/opensuse
on SATA2 harddisk...


do I have any miss to setup on FreeBSD? I do not want to reboot to linux
just because of virtualbox....

please let me know what I should do, if you use virtualbox on FreeBSD
without any problem...

thank you in advance...

from jsuk