# [SOLVED] 16gb installed only 7.95 usable.



## iciboy (Apr 3, 2010)

Hi, so i have been having this problem for awhile now. Windows recognizes 16gb but only uses 7.95, the bios finds the 16gb while memtest only sees 8gb.

I have taken them out and and switched them around etc but nothing has worked. I have not messed with the bios setting and it has just come up randomly

Specs : 

msi-990fxa-gd65
amd 8350 cpu (not oc)
xfx 7870 (not oc)

Thanks for the help in advance !


----------



## aareleb (Nov 20, 2011)

*Re: 16gb installed only 7.95 usable.*

What memory modules do you have installed? I would make sure that all modules are seated correctly, if this does not work I would remove each module and try them one at a time then in pairs.


----------



## Bill_Bright (Dec 17, 2004)

*Re: 16gb installed only 7.95 usable.*

The BIOS would not detect all if they were not seated properly. But since you said "it has just come up randomly", it might be a good idea to ensure they are fully seated in their slots and the locking mechanisms have "clicked" into place. Just make sure you unplug the computer from the wall and touch bare metal of the case interior BEFORE reaching in to discharge any destructive static in your body. 

You said this has been happening for awhile. Was the full 16Gb ever fully recognized?

Note you can pull just 1 stick at a time and use 3. This may disable dual-channel but for testing purposes, that does not matter. What matters is if your system sees the full 12Gb, or still just 8Gb.


----------



## aareleb (Nov 20, 2011)

*Re: 16gb installed only 7.95 usable.*



Bill_Bright said:


> The BIOS would not detect all if they were not seated properly. But since you said "it has just come up randomly", it might be a good idea to ensure they are fully seated in their slots and the locking mechanisms have "clicked" into place.


You are correct this most likely is not the issue but I have seen strange things happen when it comes to memory not installed correctly, so it is not so random.. I also asked what modules are installed. If they are not the same memory modules then they will not work properly.
And yes always as Bill_Bright said always unplug your system before working on it.

Aareleb


----------



## Bill_Bright (Dec 17, 2004)

*Re: 16gb installed only 7.95 usable.*



> If they are not the same memory modules then they will not work properly.


They "_may_ not" work properly, not "_will_ not". It depends on the RAM and the motherboard's chipset and memory controllers whether or not dissimilar RAM will work together, or not. 

The fact they some times do work well together suggests it is not a compatibility issue.


----------



## iciboy (Apr 3, 2010)

*Re: 16gb installed only 7.95 usable.*

Hi, sorry i wasn't able to reply but i fixed the issue. 

I unplugged the the power cable and took all the memory out along with the cmos battery left it for awhile. i put them all back in and it is now recognizing all of the memory. Thanks for the help !


----------



## Bill_Bright (Dec 17, 2004)

Interesting. Well, I hope it sticks. Thanks for the followup.


----------

