Author Options:

Why can't I use all of my computer's memory? Answered

I have 16gb installed in my asus M5A97 and in system properties it says only 7.95 is usable. Why is this? The max memory for my board is 32 gb.  



Either check in windows under control panel/system and security/system and check the amount of 'installed' memory or on POST, check the amount detected by the system - If it's less than the 16gb your DIMMs are either not seated all the way or 2 are faulty -

Try flashing your bios with the latest. My board had a problem seeing all 4 sticks until I did an update.

After the update, go into the BIOS and see if all the sticks are recognized.

What OS are you running?

Check if windows is limiting the RAM on boot.

Click start, type in 'msconfig'.  Press enter
Under the boot tab, click on advanced options
Is there a checkmark beside maximum memory?
If so, clear the checkmark and reboot.  Is all of your memory now usable?

I did that after reading a similar question, its unchecked. I just updated my bios too, nothing new...

Go into the BIOS, look for the 'memory remapping' feature in the BIOS. It should be under:
-Advanced mode
-North Bridge configuration
-Memory configuration

Make sure 'bank interleaving' and 'channel interleaving' are set to AUTO.
Make sure 'Memory hole remapping' is set to ENABLED.

If that doesn't work, can you go to resource monitor and post a screenshot of the memory tab?

What is the RAM break down (2x8, 4x4, etc)? Are you mixing sets and possible mixing specs (voltage, latency, timing, frequency)?

4x4. I didn't change any of those settings, just plugged them in

Those are intrinsic properties of the RAM not settings you can change. Did you recently upgrade and add the additional 8gb or was all the RAM purchased at once?

I bought it all with the board. Not sure if it makes a difference but I have an amd 8 core processor too

That is odd. My system has 20Gb installed but only 12 are usable. But that's due to the fact that the motherboard in my system is a dual processor board. Some of that RAM is install in the slots dedicated to the second processor. If i had a second processor i'd have access to all the memory. But that isn't the case with your board.

Does the system say you have the full 16Gb install and only 7.95 is usable, like the picture below? Have you done anything to prevent some of the RAM from being used? Such as allocating RAM to a specific function? 



5 years ago

Make sure your RAM is in the correct slots and set up right in the BIOS. Some slots may not be able to read both sides of a 2 sided module. Your modules most certainly have chips on both sides. Your slots may be only reading the chips on one side.
Next possibility is that one of the modules is defective and not working. To check that you have to try first one and then the other to see if they are both working. Also try them in different slots. Your MB manual will have specifics on how the slots should be populated.

Moral of this story.... read the motherboard manual.

Are you running a 64 bit OS or a 32 ?