pfSense

In the course of testing the amd64 builds on my various systems, I've come across a LiveCD-related issue that occurs most repeatedly on the 2.1-RC liveCD discs (manifests very sporadically and slightly differently under 2.0.x but repeatably under 2.1-RC). In particular, on multicore (>2 core) systems, the cd boot will be normal up through the following:

Configuring CRON...done.
Starting DNS forwarder...done.
Starting NTP time client...done.
Starting DHCP service...done.
Starting DHCPv6 service...done.
Configuring firewall..

And there it will stay. Ctrl-T is showing cmd: logger as being the running process. I've verified this issue to occur on multiple systems, all with >2 cores:
1st-gen core-i7 (i7-860) on an MSI P55 board
2nd-gen core-i7 (i7-2600k) on an Asus P8Z68-Deluxe
2nd-gen core-i7 (i7-2600S) on an MSI Z77A-GD65
3rd-gen core-i7 (i7-3770S) on an Intel DH77EB

The bottom three systems have been tested with a number of NIC cards, as follows: Intel onboard 82579V, Intel Gigabit Desktop CT, Intel server Pro1000/PT, Realtek 8111.

Testing with and without ATA subsystem enabled (as was suggested on the pfsense forum) makes no difference, in this case (livecd was tested using a usb cd drive as well). HOWEVER:

-memstick installer will boot reliably every time
-a hard disk install of 2.1 will boot reliably every time on the above configurations as well.

Additionally: on the above systems, disabling all but 2 cores (HT can be left on) will allow the system to boot normally. Also, booting up the system w/ no WAN cable connected will enable a successful boot as well, however, connecting the cable after this will cause the system to hang on shutdown. Increasing core count to 3 or beyond will cause the livecd to hang at the same place on subsequent boots.

I have verified the above issue to NOT occur on i3-based (dual core, HT) systems, as well as an older Atom-based system (D510)...in the case of the latter, this was done both with the onbuilt Realtek ethernet as well as with the Gigabit CT card from the above testing.

The issue ONLY seems to affect the livecd, and I have only verified this on core-i systems with more than two cores. I cannot speak for core2-quad era machines, or AMD-based multicores. I also haven't spent much time looking at the i386-based builds (realistically, though, if you're running a machine like this, why would you not run an amd64 build?).

Worst-case scenario, the workaround seems to be, "on modern systems, install from memstick?"