Missing System Memory?

mass2chaos · 11-25-2009, 05:22 AM

My MacBook Pro has 4 GB of memory (according to "About This Mac"), however when I open Activity Monitor and go to "System Memory" the number under the pie graph only reads 3.75 GB. What's missing? I checked on my friends MacBook (that has 2 GB of memory) and it read "2 GB", which is correct.

Edit: perhaps it has to do with my graphics card? I read a few threads over at Apple Discussions and they seem to be related to sharing main memory with graphics cards.

trevor · 11-25-2009, 10:36 AM

Quote:

Originally Posted by mass2chaos


	Edit: perhaps it has to do with my graphics card?

Exactly precisely which MacBook Pro do you have? What does System Profiler report about it's graphics chipset?

Trevor

mass2chaos · 11-26-2009, 02:57 AM

NVIDIA GeForce 9400M:

Chipset Model: NVIDIA GeForce 9400M
Type: GPU
Bus: PCI
VRAM (Total): 256 MB
Vendor: NVIDIA (0x10de)
Device ID: 0x0863
Revision ID: 0x00b1
ROM Revision: 3448
Displays:
Color LCD:
Resolution: 1440 x 900
Pixel Depth: 32-Bit Color (ARGB8888)
Main Display: Yes
Mirror: Off
Online: Yes
Built-In: Yes
Display Connector:
Status: No Display Connected

Gilles9 · 11-26-2009, 04:21 AM

On my iMac 20" early 2009
I have the same result as you for system memory
showing 3.75 when I have 4 in reality

trevor · 11-26-2009, 01:44 PM

Yes, the nvidia GeForce 9400M graphics chipset uses shared memory, basically using some of the system memory for video RAM. So with your graphics chipset, you will not be able to use all of your system memory for the operating system, and it makes sense for Activity Monitor to reflect that fact.

Trevor

11-25-2009, 05:22 AM	#1
mass2chaos Triple-A Player Join Date: Nov 2007 Posts: 106	Missing System Memory? My MacBook Pro has 4 GB of memory (according to "About This Mac"), however when I open Activity Monitor and go to "System Memory" the number under the pie graph only reads 3.75 GB. What's missing? I checked on my friends MacBook (that has 2 GB of memory) and it read "2 GB", which is correct. Edit: perhaps it has to do with my graphics card? I read a few threads over at Apple Discussions and they seem to be related to sharing main memory with graphics cards. Last edited by mass2chaos; 11-25-2009 at 05:30 AM.

11-26-2009, 04:21 AM	#4
Gilles9 Triple-A Player Join Date: Jun 2008 Location: Montréal, QC Posts: 82	On my iMac 20" early 2009 I have the same result as you for system memory showing 3.75 when I have 4 in reality __________________ Gilles imac 20" (early 2009) Mac 10.6.5

11-26-2009, 01:44 PM	#5
trevor Moderator Join Date: Jun 2003 Location: Boulder, CO USA Posts: 19,560	Yes, the nvidia GeForce 9400M graphics chipset uses shared memory, basically using some of the system memory for video RAM. So with your graphics chipset, you will not be able to use all of your system memory for the operating system, and it makes sense for Activity Monitor to reflect that fact. Trevor __________________ How to ask questions the smart way

Thread Tools
Show Printable Version Email this Page
Display Modes	Rate This Thread
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode	Rate This Thread:

11-26-2009, 02:57 AM	#3
mass2chaos Triple-A Player Join Date: Nov 2007 Posts: 106	NVIDIA GeForce 9400M: Chipset Model: NVIDIA GeForce 9400M Type: GPU Bus: PCI VRAM (Total): 256 MB Vendor: NVIDIA (0x10de) Device ID: 0x0863 Revision ID: 0x00b1 ROM Revision: 3448 Displays: Color LCD: Resolution: 1440 x 900 Pixel Depth: 32-Bit Color (ARGB8888) Main Display: Yes Mirror: Off Online: Yes Built-In: Yes Display Connector: Status: No Display Connected