Only 8 out of 16GB ram is visible in Windows 7 64bit

TheSandman2236 · Feb 28, 2013, 11:33 AM

I'm running a brand new Late 2012 i7 iMac with Fusion Drive, 16GB of ram, etc. I just put a bootcamp partition with WIndows 7 Pro x64 on the Fusion Drive today and after all the drivers and updates were applied the system does not allow usage of the full 16GB installed in the machine (this was also the case prior to driver/updates installation). Can anyone supply a solution or a reason why this is the case?

HurtinMinorKey · Feb 28, 2013, 12:56 PM

Aren't some versions of Windows 7 RAM limited. You may need ultimate or pro to go above 8gb of ram?

TheSandman2236 · 01:19 PM

Quote:

Originally Posted by HurtinMinorKey

Aren't some versions of Windows 7 RAM limited. You may need ultimate or pro to go above 8gb of ram?

I'm using Windows 7 Pro x64 -- plus I have 16GB RAM on my Windows Desktop.

FreemanW · Feb 28, 2013, 01:50 PM

Quote:

Originally Posted by HurtinMinorKey

Aren't some versions of Windows 7 RAM limited. You may need ultimate or pro to go above 8gb of ram?

No.

The RAM limitation in Windows has to do with 32-bit versus 64-bit. The limit of addressable memory in 32-bit is 4GB. Because of the way in which Windows uses memory and begins addressing memory for processes, it works down from 4GB, so a 32-bit Windows installation with 4GB of memory may show anywhere between 3.5GB down to 2.8GB of system memory.

The OP is very likely facing a limitation of the BootCamp environment in which he has Windows installed and running.

I've never had the occasion to play with BootCamp, so that is as far as I can speculate.

WilliamG · Feb 28, 2013, 02:28 PM

No issues here with 32GB RAM 2012 iMac running Windows 7 64bit.

Bobbymoon · Feb 28, 2013, 04:24 PM

Quote:

Originally Posted by TheSandman2236

I'm running a brand new Late 2012 i7 iMac with Fusion Drive, 16GB of ram, etc. I just put a bootcamp partition with WIndows 7 Pro x64 on the Fusion Drive today and after all the drivers and updates were applied the system does not allow usage of the full 16GB installed in the machine (this was also the case prior to driver/updates installation). Can anyone supply a solution or a reason why this is the case?

I have the exact same machine and problem.

I have two different brands of RAM (stock ram & Crucial ), could this be the reason maybe?

kpgh554 · Feb 28, 2013, 05:15 PM

Quote:

Originally Posted by Bobbymoon

I have the exact same machine and problem.

I have two different brands of RAM (stock ram & Crucial ), could this be the reason maybe?

It's a windows thing as my brothers have pcs and they get same, windows only uses 8gb even after they've added 16gb to their pc's. i think pc's use virtual memory mostly why they put on hdd an unallocated space to use as virtual memory. that my thoughts i maybe wrong.

WilliamG · 05:43 PM

Quote:

Originally Posted by kpgh554

It's a windows thing as my brothers have pcs and they get same, windows only uses 8gb even after they've added 16gb to their pc's. i think pc's use virtual memory mostly why they put on hdd an unallocated space to use as virtual memory. that my thoughts i maybe wrong.

How are you determining that Windows is only using 8GB? I disabled all virtual memory in Windows 7 64bit, since 32GB is more than I would ever need.

drambuie · Feb 28, 2013, 06:26 PM

Quote:

Originally Posted by TheSandman2236

I'm running a brand new Late 2012 i7 iMac with Fusion Drive, 16GB of ram, etc. I just put a bootcamp partition with WIndows 7 Pro x64 on the Fusion Drive today and after all the drivers and updates were applied the system does not allow usage of the full 16GB installed in the machine (this was also the case prior to driver/updates installation). Can anyone supply a solution or a reason why this is the case?

Type msinfo32.exe in the start menu. It should give the physical and virtual memory status.

Nuke61 · Feb 28, 2013, 09:09 PM

A *possible* solution... as a user with Administrator rights, run 'msconfig'

Select Boot tab, and then Advanced Options, then Maximum Memory. If it's checked, uncheck it and do a cold reboot.

jenzjen · Feb 28, 2013, 09:17 PM

I have 2 machines that show my full RAM under W7 professional x64 - 24Gb and 16Gb - so I doubt it is a Windows limitation, as long as you're running a 64bit version.

FreemanW · Mar 1, 2013, 12:16 AM

Quote:

Originally Posted by WilliamG

No issues here with 32GB RAM 2012 iMac running Windows 7 64bit.

Hey WmG, you're running with BootCamp, nes pas?

WilliamG · Mar 1, 2013, 12:59 AM

Quote:

Originally Posted by FreemanW

Hey WmG, you're running with BootCamp, nes pas?

Yep.

TheSandman2236 · Mar 1, 2013, 06:55 AM

Looks like I may have two bad RAM slots. Swapping it out tonight :/

Feb 28, 2013, 11:33 AM	#1
TheSandman2236 macrumors 6502 Join Date: Mar 2008 Location: Atlanta, GA	Only 8 out of 16GB ram is visible in Windows 7 64bit I'm running a brand new Late 2012 i7 iMac with Fusion Drive, 16GB of ram, etc. I just put a bootcamp partition with WIndows 7 Pro x64 on the Fusion Drive today and after all the drivers and updates were applied the system does not allow usage of the full 16GB installed in the machine (this was also the case prior to driver/updates installation). Can anyone supply a solution or a reason why this is the case? __________________ iPhone 5 16GB AT&T + iPad Mini 32GB AT&T
	0

Feb 28, 2013, 12:56 PM	#2
HurtinMinorKey macrumors regular Join Date: Jan 2012	Aren't some versions of Windows 7 RAM limited. You may need ultimate or pro to go above 8gb of ram? __________________ www.carolineculler.com
	0

Feb 28, 2013, 02:28 PM	#5
WilliamG macrumors 68040 Join Date: Mar 2008 Location: Seattle	No issues here with 32GB RAM 2012 iMac running Windows 7 64bit. Attached Thumbnails __________________ iMac, MacBook Air, Mac mini, iPad, iPhone, 55-11 www.bighugenerd.com
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Mar 1, 2013, 06:55 AM	#14
TheSandman2236 Thread Starter macrumors 6502 Join Date: Mar 2008 Location: Atlanta, GA	Looks like I may have two bad RAM slots. Swapping it out tonight :/ __________________ iPhone 5 16GB AT&T + iPad Mini 32GB AT&T
	0

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Feb 28, 2013, 09:09 PM	#10
Nuke61 macrumors regular Join Date: Jan 2013 Location: Oceanside, Ca	A possible solution... as a user with Administrator rights, run 'msconfig' Select Boot tab, and then Advanced Options, then Maximum Memory. If it's checked, uncheck it and do a cold reboot.
	0

Feb 28, 2013, 09:17 PM	#11
jenzjen macrumors 65816 Join Date: Aug 2010	I have 2 machines that show my full RAM under W7 professional x64 - 24Gb and 16Gb - so I doubt it is a Windows limitation, as long as you're running a 64bit version.
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