CROSSHAIR IV FORMULA memory trouble

[PLAYDODGY]

I have the crosshair iv formula 785g chipset running amd 955 quad, 16GBytes dual channel DDR3 2000 MHz corsair .
It only list 4GBytes in the system, is there something I have to change in bios, etc, or is it a board fault, got second hand runs mint no problems, just the problem not recognising the full 16GBytes of ram, I know some stuff,but cant figure this out ,.
Any help advice, or settings would be very greatfull.
p.s this is my first post of many I hope, and thanks in advance

[liammcd]

Sounds like the usual 4Gb limit of a 32-bit OS.

Does the BIOS report 4Gb or 16Gb?

[PLAYDODGY]

Sorry my mistake , wont boot with more than 1 stick in it ,

[PLAYDODGY]

will have to wire the board up to find out what BIOS reports
take me a little while will let you know shortly

[liammcd]

Can you also post the part numbers of the memory sticks?

According to the Asus support pages, that motherboard officially only supports up to 4Gb per memory socket, (although that doesn't actually mean that it doesn't work, just probably that Asus didn't test bigger DIMMs).

You said that it "wont boot with more than 1 stick in it". Does it boot up properly with one stick?

Does it matter which stick?

Which memory slots are you populating? Motherboards can be fussy about paired memory sockets.

[Bonebreaker777]

Agree with the previous post.
If you could answer the following questions, it would makea huge difference in terms of troubleshooting.
Does it boot with one stick only?
Does it boot with the same stick only or as long you have only one stick installed you can boot with any stick?
Does it boot in one slot only?
Does it boot in different memory slots?
Combine and test the situations described roughly by the questions above and report back with your findings, please.
Good luck!