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RhysThornbery

macrumors newbie
Original poster
May 28, 2013
4
0
So im using a Power Mac 2009 Model. I've Boot camped Windows 7 32bit onto a partition on my hard drive. However while using this side of the hard drive I noted an anomaly. of the 16 GB of Ram installed on the computer only 2 GB of it are not "Reserved for Hardware". After some study I found that this is a fairly common issue with windows 7 32bit. The fix they suggest is upgrade the system BIOS (the equivalent of firmware as I understand it) alright fair enough. But i'm running all this off a mac. How do I do this? without messing up either side of the partition?:confused:
 
Last edited:

superriku11

macrumors member
Jun 16, 2012
58
0
United States
So im using a Power Mac 2009 Model. I've Boot camped Windows 7 32bit onto a partition on my hard drive. However while using this side of the hard drive I noted an anomaly. of the 16 GB of Ram installed on the computer only 2 GB of it are not "Reserved for Hardware". After some study I found that this is a fairly common issue with windows 7 32bit. The fix they suggest is upgrade the system BIOS (the equivalent of firmware as I understand it) alright fair enough. But i'm running all this off a mac. How do I do this? without messing up either side of the partition?:confused:

Well for one, BIOS doesn't have do to with your hard drive partitions. BIOS is the firmware, like you said. Except firmware typically means EFI, which is what OS X uses by default, and that Linux, and recent versions of Windows are capable of using. BIOS is different, being that it is old, outdated, and should be replaced with EFI.

However I've never heard of this problem before. At first glance of the thread title I assumed you probably installed a version of Windows that can't use all your RAM. And I'm still inclined to think you most likely did.

32bit versions of Windows are limited to using 4 GB of RAM at most, as that is an addressing limit of 32bit architecture. You need a 64bit version of Windows 7 to utilize all your RAM.

On top of that, you need a version that will allow full use of your 16 GB of RAM. For some odd reason, Microsoft wants to restrict the amount of RAM certain versions of Windows can use, even when a realistic technical limitation does not exist. As I said before, 32bit Windows can use up to 4 GB of RAM. However yours is only using 2 GB most likely due to your version.

From the information you've provided, I've deduced that you're most likely using Windows 7 Starter. Which is limited to 2 GB of RAM on 32bit systems.

In order to use your full 16 GB of RAM, you will need Windows 7 Home Premium x86_64 (x64) or higher. Higher meaning the more expensive versions that are still 64bit.

If you're wondering where I'm getting these numbers and this information, Microsoft has it laid out simply here: http://msdn.microsoft.com/en-us/library/windows/desktop/aa366778(v=vs.85).aspx#physical_memory_limits_windows_7
 

RhysThornbery

macrumors newbie
Original poster
May 28, 2013
4
0
Well for one, BIOS doesn't have do to with your hard drive partitions. BIOS is the firmware, like you said. Except firmware typically means EFI, which is what OS X uses by default, and that Linux, and recent versions of Windows are capable of using. BIOS is different, being that it is old, outdated, and should be replaced with EFI.

However I've never heard of this problem before. At first glance of the thread title I assumed you probably installed a version of Windows that can't use all your RAM. And I'm still inclined to think you most likely did.

32bit versions of Windows are limited to using 4 GB of RAM at most, as that is an addressing limit of 32bit architecture. You need a 64bit version of Windows 7 to utilize all your RAM.

On top of that, you need a version that will allow full use of your 16 GB of RAM. For some odd reason, Microsoft wants to restrict the amount of RAM certain versions of Windows can use, even when a realistic technical limitation does not exist. As I said before, 32bit Windows can use up to 4 GB of RAM. However yours is only using 2 GB most likely due to your version.

From the information you've provided, I've deduced that you're most likely using Windows 7 Starter. Which is limited to 2 GB of RAM on 32bit systems.

In order to use your full 16 GB of RAM, you will need Windows 7 Home Premium x86_64 (x64) or higher. Higher meaning the more expensive versions that are still 64bit.

If you're wondering where I'm getting these numbers and this information, Microsoft has it laid out simply here: http://msdn.microsoft.com/en-us/library/windows/desktop/aa366778(v=vs.85).aspx#physical_memory_limits_windows_7

Alright. Considering everything you've told me and everything i'm able to look up i agree we with you and am gonna try installing the 64 bit version. we'll see if that fixes it.
 

RhysThornbery

macrumors newbie
Original poster
May 28, 2013
4
0
Yup that was the problem. Save for a few dozen MB all my ram is now active. Thanks for the advice.
 

superriku11

macrumors member
Jun 16, 2012
58
0
United States
Yup that was the problem. Save for a few dozen MB all my ram is now active. Thanks for the advice.

If you installed Windows 7 Home Premium 64bit, then your maximum RAM is 16 GB. If I remember correctly, the RAM limits in Windows are actually slightly lower than what they say. Which would explain why a few MB aren't being used.

If you really wanted those extra MBs, you could install a higher version that allows use of more than 16 GB. But realistically you probably won't need those extra few MBs, so it won't matter.
 

RhysThornbery

macrumors newbie
Original poster
May 28, 2013
4
0
nope dont need those extra mbs. was just noting the difference. 15.something gigs of ram is way beyond more than enough.
 
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