ZFS on top of GELI / Intel Atom 330 system

[Morgan Wesström]

Dan Naumov wrote:
> Thank you for your numbers, now I know what to expect when I get my
> new machine, since our system specs look identical.
> 
> So basically on this system:
> 
> unencrypted ZFS read: ~70 MB/s per disk
> 
> 128bit Blowfish GELI/ZFS write: 35 MB/s per disk
> 128bit Blowfish GELI/ZFS read: 24 MB/s per disk
> 
> I am curious what part of GELI is so inefficient to cause such a
> dramatic slowdown. In comparison, my home desktop is a
> 


You can benchmark the encryption subsytem only, like this:

# kldload geom_zero
# geli onetime -s 4096 -l 256 gzero
# sysctl kern.geom.zero.clear=0
# dd if=/dev/gzero.eli of=/dev/null bs=1M count=512

512+0 records in
512+0 records out
536870912 bytes transferred in 11.861871 secs (45260222 bytes/sec)

The benchmark will use 256-bit AES and the numbers are from my Core2 Duo
Celeron E1200 1,6GHz. My old trusty Pentium III 933MHz performs at
13MB/s on that test. Both machines are recompiled with CPUTYPE=core2 and
CPUTYPE=pentium3 respectively but unfortunately I have no benchmarks on
how they perform without the CPU optimizations.

I'm in the same spot as you, planning to build a home NAS. I have
settled for graid5/geli but haven't yet decided if I would benefit most
from a dual core CPU at 3+ GHz or a quad core at 2.6. Budget is a concern...

Regards
Morgan