Yesterday I build a new i5 rig basing on a Gigabyte GA-P55-USB3 mainboard. i5 760 GA-P55-USB3 4x2GB Corsair XMS3 CMX4GX3M2A1600C9 ATI HD 6870 The mainboard has recognized the four RAM modules, but only uses the first and second slot: DIMM Slot (MB) 1: 2048 2: 2048 3: 2048 4: 2048 Enabled Slot (MB): 1: 2048 2: 2048 How can I get the board to use all four modules?
that in the bios ? if so what happens if you disable slots 1 and 2 option and it may revert to using all 4 rather than been forced to use just those 2 ?
It seams that your RAM is supported based on people asking on multiple forums and I can't find any similar complaints. Did you touch any memory settings in the BIOS? Did you set Enabled XMP to Profile1? If not, please do so. See is memTest can see your extra stick of RAM, if so, run a diagnostic. If not, in the BIOS, select "Load Optimized Default" save and reboot. See if there is any progress. If not, make sure that the RAM is well inserted on your board. If no progress, then it might be faulty. Try different RAM stick if you can (ask a friend?), to make sure that it's not a motherboard issue.
Take a rubber (eraser) to the memory contacts and check the sockets for damage. After you reset the CMOS defaults it should automatically see the ram - there's no BIOS setting. Rotate the memory in the slots - check if the two DIMM banks are dead vs the actual memory
Thank you for your kind replies! The board does recognize the four sticks, and so does Windows. In Windows it says 8GB RAM (3.99 usable). However dual channel seems to be deactivated and there seems to be no option to activate it. Under MIT Current Status where the bios lists all the different information about your system the 4 sticks are listed, but only the first and second are used. The third and fourth are recognized but not enabled. The manual advises to install the RAM to the first and third slot if only two are used, so as said I think Dual Channel is deactivated and I cannot find the option to activate it.
That is what I was about to ask. What is your OS? and what version you use? If you don't know, Start > Computer > System Properties (Vista/Win7 - else right-click on Computer and select Properties for XP) . On that panel, it should say if it's a 32 or 64-bit system. Also refer to your motherboard instruction manual, to make sure that the RAM placement is set correctly for dual channel. If you only have 2 stick of RAM, the position really maters.
Nope, Win 7x64 Professional. Again, I am using FOUR sticks of RAM, which ALL are recognized correctly, but only TWO are used, only one stick per channel instead of two. I am NOT talking about Windows here, but the bios settings!
Alright, one stick seems to be faulty. Tested them one by one. Damn. Never had a faulty stick that has been recognized but couldn't be used by the mainboard. Ah well, I'll RMA it. At least I still have 4GB to use for now. Thank you for your help, really appreciate it! +Rep
Yea the MIT will show the RAM 'is there' but the latencies will not appear if the slots are knackered or the memory contacts are not all electrically sound (do the eraser trick on them). Did you rotate the sticks to check as well? EDIT: Ah OK you just replied at the same time
