DAO syncing very slow and with high load

my DAO syncing reaches only about 1 block transactions parsing per second with 2 CPU cores at 170% load.
My DAO sync process takes a long time and makes the system slow to respond.
Reniceing the bisq process to the lowest priority (19) helps a lot to regain a responsible system.
Is 1 DAO block transactions parsing per second normal on a 2 CPU/2.53 Ghz Linux system ? Or is this a design flaw ?
I think starting the DAO sync thread with priority 19 would make things a lot better for almost everyone.
A slow down of the DAO sync is not noticeable with priority 19.