Performance of Geli compared to Luks

[Dan Nelson]

In the last episode (Mar 25), Moritz Schlarb said:
> My HP Proliant Microserver, which I want to use as a NAS, is using an AMD
> Turion II Neo N40L processor.  The plain disks give me about 100 MB/s
> using filebench with the fivestreamwrite/multistreamwrite workloads (as
> software RAID-1 under Linux and zpool mirror under FreeBSD).
> 
> In Linux, using LUKS with cipher aes-xts-plain64 on a software RAID-1 I
> get the same ~100 MB/s for the same benchmarks.
> 
> In FreeBSD, using a mirror zfs pool with underlying GELI with AES-XTS I
> get only ~50 MB/s.
> 
> As the encryption algorithms should be the same, I'm wondering why FreeBSD
> is that slow for nearly exactly the same use case.  Any ideas how I could
> tweak my settings in FreeBSD?

As a first step, I'd try reading/writing from the raw GELI and LUKS devices
to rule out performance differences due to the filesystems you're using.

-- 
	Dan Nelson
	dnelson at allantgroup.com