Some post from official corsair support peeps to clear up and verify 1T/2T issue on A64 systems lies in memorycontroller limitation with
large memory pool spread out on many chips/banks.(link at the bottom) .All DS memory modules (incl. value) and their PCB manage 1T command today.
The time that modules themselves didn't manage 1T was in the old days using slow sdram/edoram .And external chipset /northbridge memory controller
played a more important role .
Anyone that has been overclocking nForce2 system with 2*256MB single side/bank modules vs 2*512MB double side/bank knows about the
CPC on/off thing (1T/2T) and when it hits you in the face and have to disable it much earlier with 2*512 Dual side/bank .
You see the same today on A64 plattforms , those who goes for records (benchmark junkies) run their system in this circumstance with 2*256MB Single bank
oldies with BH5 chips.
To ease your mind with confirmation of 4*512 and 2T , look at: http://www.houseofhelp.com/forums/showthread.php?t=46070