One lone stck should
work in any
slot; I always tell people to use the first one as it minimizes skew, and should be the easiest slot to get working. Memory is made to JEDEC specifications:http://www.jedec.org/
It contains a little piece of EEPROM memory called an SPD - this contains a set of parameters that 'tell' the motherboard how to 'set itself' to accomodate the memory; all memory is basically JEDEC spec'd RAM; DDR2 has a standard voltage of 1.8V; DDR3 is 1.5V; all memory is required to run, as a minimum, at that specified voltage. What is done is, when a memory manufacturer designs a module for higher speeds, they often specify a higher voltage to achieve that higher data rate - but
- it still must meet JEDEC spec - it must
run low speed at the JEDEC voltage. I don't have anything here that runs DDR3, so this is the SPD from a piece of DDR2 - the principle is the same:
Note that for the first three table entries, the voltage is 1.8V - this is the JEDEC specification for DDR2, and it must
boot at that voltage. Now, look at the table in the fourth slot, labelled EPP#1; this is the set of parameters for my RAM to run at higher speed, and you can see that this is spec'd at 2.1V
The "Load Optimized Defaults" option in your BIOS forces the BIOS to read this higher voltage/speed info and set itself accordingly; these settings will then work for all four slots.
So, yes, the initial boot will work, as it can run any memory at JEDEC voltage and specs, which all memory must meet...