Ram only recognised at half volume...8gb instead of 16gb

[Goanna1]

Now that the Kuban release is imminent I finally got my gaming computer up and functioning extremely well after months of woes and inactivity causing me to shelve the project.

 

I have an issue where the ASUS Sabretooth Z77 motherboard only recognises the  RAM as half what is present 8gb instead of 16gb, (RAM is Corsair Dominator 2666mhz..8gb sticks x2..only recognised as and stably works as 2x 4gb 1866mhz RAM sticks. Got me stumped as I've checked BIOS (upgraded that to the latest edition as well) and anything else I can think of.. Any tech knowledge and input from the geniuses here will be greatly appreciated.

I had another issue when I downloaded and installed the latest Nvidia drivers (390.77 for windows 10 x64)where the GPU fan ran on in high speed mode when computer was turned off ... only way to stop that was to turn power off at rear power supply switch. A reinstall 3rd one tried seems to have fixed that issue ...but this happened after I first noticed RAM problem. Ram isnt stable at 2666 only at top speed of 1866, and is isn't o/clocked.

 

Any tech knowledge and input from the geniuses here will be greatly appreciated.

regards Paul

[Mitthrawnuruodo]

Look in the motherboard manual to make sure you're using the two correct RAM slots and try reseating the sticks.

 

If it's the BIOS saying that there is 2 x 4 GB, you might not have 8 GB sticks. Perhaps you could look up the part number on the sticks to make sure there hasn't been some silly mistake?

[Seb71]

^Yeah. Could be that. Kits of two modules (sticks) are sometimes advertised as the total RAM size and you could think it's the RAM size per stick.

 

If you are sure you got 8GB sticks, first test would be with only one module at a time (in the same MB slot). If both are recognized individually as 8GB, then test with only one module in each MB slot (to check that all slots are working). Make sure you shut down and unplug the PC between RAM replacements (also discharge the capacitors by pushing the power button with the PC unplugged from power).