Freebsd on NSA 7130 (NEXCOM)

I would also hit the BIOS and make sure that it all looks right.

Some things I would fiddle with include C states and disabling HyperThreading for experimenting.

Since it seems to be related to irq16, which is your SATA controller I would also make sure that hard drive mode is set to AHCI instead of IDE.
I do notice that vgapci0 using irq 16 on bus pci7 seems to be grabbing the interrupt before ahci0 SATA controller on pci0 using irq16
I still think its the same symptom. Network interfaces are using all the irq's.
Maybe quirky ACPI bios. Have you looked for newest firmware?
I know these OEM'ers don't offer much for public download support.
Can you try and disable the NIC's in the bios? I see igb8 up there. How many interfaces does it have?
Thank you Phishfry for your help. As you said the system had run out of IRQs.
So I did a few tests that show limiting hw.igb.num_queues to a maximum of 3 solves the problem.

So the system is now up and running. But I am concerned about the performance implications of setting just 1 queue (CPU core) per interface.

This system has 22 interfaces (10 x 1Gb and 12 x 10Gb), and 2 x Xeon processors with a total of 24 processing threads.

Does this mean that (assuming all net interfaces are being used) hw.igb.num_queues=1 should be OK?
This would be a good question for IRC or mailing lists. It is well above my skills to offer such advice...
Glad you got it running though. It is a sweet ride.