Having built two new systems based on Asus P5Q Pro and P5K SE lately, I have noticed differences in the way they operate compared to others before.
1) There is a pause on boot:
This happens when I turn off the psu for whatever reason. On system boot, it comes to life then turns off for a few seconds. Then It turns itself back on and keeps booting.
Whenever a bios change is made and the change is saved, I reboot and the same thing happens.
2) There is a change in cpu clock speed at idle:
Although I have not installed the new EPU power saving software, they automatically reduce the multiplier. In the case of my overclocked e4300 running at 333 fsb @ 3Ghz, at idle it is running at x6 @ 2Ghz. The moment the cpu is called upon for a task it jumps to x9 @ 3Ghz.
1) Yes, the new P45 boards (I have a few) all do that dual start.
2) Nope, none of my boards with all the options disabled do that. They all run at the specified Vcore and multi, as selected in the BIOS.
1) My P35 board does that too, and my X38 will do it after a full power-down (PSU actually turned off). As I understand it, it's just a quick double-check by the board before fully powering on.
2) Shouldn't be an issue, although if your FSB is high enough, it's not impossible that the reduced voltage might not be enough to power the chip at 6xFSB. Only a theory, though. I've never actually encountered it myself, since I always disable Speedstep.
i7 2600K | ASUS Maximus IV GENE-Z | GTX Titan | Corsair DDR3-2133