Installed memory in DIMM B of both channels. SNB native raminit reports memory in DIMM A?

[Keith Hui]

I'm having more fun with my P8Z77-M.

I put my two sticks of GSkill Ripjaws in slots A2 and B2 (aka C0S1,
C1S1) following manual recommendations.

Surprise 1: It actually worked at full speed now! It previously would
totally croak, at least when I hook up serial to watch things go.
Installing only one at C1S0 still didn't boot. And that's with me
putting my max memory clock back to 800.

Surprise 2: This is why I'm writing this email. I got this in the console:
...
[DEBUG]  memcfg DDR3 ref clock 133 MHz
[DEBUG]  memcfg DDR3 clock 1596 MHz
[DEBUG]  memcfg channel assignment: A: 0, B  1, C  2
[DEBUG]  memcfg channel[0] config (00630020):
[DEBUG]     ECC inactive
[DEBUG]     enhanced interleave mode on
[DEBUG]     rank interleave on
[DEBUG]     DIMMA 8192 MB width x8 dual rank
[DEBUG]     DIMMB 0 MB width x8 single rank, selected
[DEBUG]  memcfg channel[1] config (00630020):
[DEBUG]     ECC inactive
[DEBUG]     enhanced interleave mode on
[DEBUG]     rank interleave on
[DEBUG]     DIMMA 8192 MB width x8 dual rank
[DEBUG]     DIMMB 0 MB width x8 single rank, selected
...

Am I seeing things? Why did it report memory in DIMMA when I put my
memory in slot 1 only?

Regards
Keith