Roughly how long does it take to build the cross reference in AX 2012 R2?

Roughly how long does it take to build the cross reference in AX 2012 R2? I’m trying to get some metrics because I think my virtual machines may be performing slowly.

I have a machine with 8 cores and 8gb of memory and building the cross reference in AX 2012 R2 CU7 so far has been running for over 5 days.

I usually stop after a night, if it still keeps on running. I see the x-refs are updated properly…

It took me about 16 hours last time (using a large Azure virtual machine).