High detail reconstruction issue

It pushed another day now, its really my ram usage goes from 30%-80% during the day and my CPU almost never gets used or GPU. sometimes i see my harddrive working at around 5-30MB/s. 

If my ram is hardly being used why on earth is this taking so long? it seems like there is a bug?

 
I should note the reconstruction is of a large interior floor.

Should I assume just pausing and resuming should solve the problem as per the FAQ for large scenes? is this being addressed in a future release?

Thx!