# Windows 7 Home Premium x64: 16GB RAM installed, only 13.5GB available



## Red_Machine (Aug 30, 2011)

I have a friend who just upgraded her rig to 16GB of RAM, but Windows reports only 13.5GB is useable.  A google search turned up nothing, so I thought I'd ask here.

Cheers in advance.


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## erocker (Aug 30, 2011)

What motherboard?


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## Sinzia (Aug 30, 2011)

We need more info about the system in order to help


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## crazyeyesreaper (Aug 30, 2011)

16gb max the person has a GTX 480 = 1.5gb + 13.5 = 15gb i think its just a software limit of 64bit home premium,

becuase it takes 4x4gb = 16 means all 4 sticks are being recognized  3 sticks is 12 so yea im thinking its the built in limit on 64bit home premium

just as 32bit is limited to 4gb but you only every get 3.2gb


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## Red_Machine (Aug 30, 2011)

http://usa.asus.com/Motherboards/Intel_Socket_1366/P6X58D_Premium/


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## crazyeyesreaper (Aug 30, 2011)

uh... 16gb on x58 yea thats fail

4x4x4 = 12
4x4x4+4x4x4= 24

2x2x2 = 6
2x2x2+2x2x2 =12

she shouldnt have 16gb on that board. unless running dual channel which makes no sense on an x58 board

theres no way to have 16gb unless shes mixing and matching ram or running dual channel I smell epic fail.


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## Red_Machine (Sep 8, 2011)

She pulled one of the sticks out, so she's now running 4x4x4.  But, Windows is reporting 12 insalled, 12 total, but 9.17 avilable.

So basically the same issue as before, just with less RAM.  Any ideas?


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## mtosev (Sep 8, 2011)

update the bios,clear cmos settings and load default bios settings


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## silkstone (Sep 8, 2011)

Red_Machine said:


> She pulled one of the sticks out, so she's now running 4x4x4.  But, Windows is reporting 12 insalled, 12 total, but 9.17 avilable.
> 
> So basically the same issue as before, just with less RAM.  Any ideas?



Where in windows is this being reported? System info?


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## H82LUZ73 (Sep 8, 2011)

Red_Machine said:


> I have a friend who just upgraded her rig to 16GB of RAM, but Windows reports only 13.5GB is useable.  A google search turned up nothing, so I thought I'd ask here.
> 
> Cheers in advance.



so it uses 3.5 gig for windows right.The 13.5 is free ram.

http://www.sevenforums.com/general-discussion/8446-windows-7-ram-usage.html


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## Millennium (Sep 8, 2011)

I had a problem with 8gb installed 4gb usable and simple swapping the ram around fixed it. Not sure if this applies to x58 too, this was on p55


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## 95Viper (Sep 8, 2011)

Red_Machine said:


> Windows reports only 13.5GB is useable



Maybe this>  The usable memory may be less than the installed memory on Windows 7-based computers


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## newtekie1 (Sep 8, 2011)

I've seen this issue before if the heatsink is too tight and causing the board to warp.  Just an idea though.


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## twicksisted (Sep 8, 2011)

show us a screenshot of your task manager
I have 16gb memory and heres what my taskmanager says:







Windows uses superfetch to cache files for quicker access which takes up some of the ram.


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## repman244 (Sep 8, 2011)

Available ≠ Total

Resource monitor from task manager (8GB of RAM):


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