CTA archive running slow

NS80 with 4 DMs and CTA is configured to archive files to Centera. We were using DX for NAS and it was migrated to CTA recently.. Started running CTA archive jobs and notice that archive process is runnign really slow. It is doing archive of 2-5GB of data per day. Is this device operate this slow generallly? I have a case open with Support and they say if the folders are too deep it has to go through each and every folder and it takes long time to archive. We have an avarage of 5-6 levels of subdirectories for all users and it should not take that much time to archive. Any idea guys?