zfs vs svm: peformance consideration

Hello all,I have a T4-1 configured with a boot disk configured as an svm mirror and I have another t4-1 configured with a zfs mirror for the boot disk.

Doing some preliminary check to compare behaviours I found that the tar -x of the same 2GB file on /var/tmp/ (/var is a separate fs in both cases) is performing worse on the zfs configuration

Time to complete on svm  config :

real        1:01.44
user           8.17
sys           29.07


time to complete on zfs config

real        1:49.13
user           9.17
sys         1:33.64


I'm starting the investigation but before to start I would like to understand if I'm simply missing something basic here.