FSAUtility -pm migration rate

Hi

I've read articles on how FSAutility performance can be improved by increasing threads etc but what is a a good rate anyway? Are there any indicative baselines that I can work with?

I'm just looking for a rough timeline for perhaps migrating 4 million placeholders as part of a hardware refresh - would that perhaps be 1 hour? day? week or month roughly?

I would say we have a typical EV12 environment using 1Gbe networks, EV server (vm) has 16 cores and 32GB RAM and storage is on a NetApp..... but I'm just looking to move placeholders here not archived data.

perhaps others have already done this and can offer some real world experiences?

many thanks