AppleInsider › Forums › Mac Hardware › Current Mac Hardware › Windows only seeing 3Gb on a new 4Gb 24" iMac?
New Posts  All Forums:Forum Nav:

Windows only seeing 3Gb on a new 4Gb 24" iMac?

post #1 of 7
8/15/07 at 7:40am
Thread Starter 
Hi, I've kept away from Windows for the best part of a decade but decided to boot camp vista ultimate on my new 2.4Ghz, 24", 4Gb, 320Gb iMac - for some reason windows only recognises 3Gb of memory - is that right?
Reply
Reply
post #2 of 7
8/15/07 at 7:44am
Are you using the 32bit or 64bit version of Vista?

I belive there is a limitation in the 32bit version which limits you to using 3GB of RAM (even though theoretically you should be able to access 4GB).

edit: found a Microsoft knowledgebase article about it: http://support.microsoft.com/kb/929605

Quote:
The reduction in available system memory depends on the devices that are installed in the computer. However, to avoid potential driver compatibility issues, the 32-bit versions of Windows Vista limit the total available memory to 3.12 GB. See the "More information" section for information about potential driver compatibility issues.

They also list a workaround which involves going into the BIOS and playing around with some settings. However, trying to do that on a iMac that uses EFI instead of BIOS might be a bad idea... I don't know exactly how Boot Camp fools Windows into thinking there is a BIOS, or if there is some kind of legacy BIOS emulation in EFI. Either way, it's not something you want to mess with unless you don't mind breaking your new iMac
Reply
Reply
post #3 of 7
8/15/07 at 7:53am
Thread Starter 
Quote:
Originally Posted by yama View Post

Are you using the 32bit or 64bit version of Vista?

I belive there is a limitation in the 32bit version which limits you to using 3GB of RAM (even though theoretically you should be able to access 4GB).

edit: found a Microsoft knowledgebase article about it: http://support.microsoft.com/kb/929605

Yes it is the 32-bit version as boot camp only deals with 32b versions afaik. Thanks for the tip-off anyway.
Reply
Reply
post #4 of 7
8/15/07 at 9:07am
Quote:
Originally Posted by Chopper3 View Post

Yes it is the 32-bit version as boot camp only deals with 32b versions afaik. Thanks for the tip-off anyway.

Interesting, I didn't realise Boot Camp only worked with 32bit versions of Windows... I wonder if this will change with Leopard. I know that VMWare Workstation on Windows and Linux has experimental support 64bit OSes - anybody kow if Parallels or VMWare Fusion do as well?
Reply
Reply
post #5 of 7
8/15/07 at 9:08am
Quote:
Originally Posted by yama View Post

Interesting, I didn't realise Boot Camp only worked with 32bit versions of Windows... I wonder if this will change with Leopard. I know that VMWare Workstation on Windows and Linux has experimental support 64bit OSes - anybody kow if Parallels or VMWare Fusion do as well?

Fusion support 64-bit guests. Parallels does not.
MacBook Pro 15" Core i7 (8GB RAM, 1TB HD)
iPhone 4 32GB, iPhone 3GS 32GB, iPhone 2.5G 8GB
Reply
MacBook Pro 15" Core i7 (8GB RAM, 1TB HD)
iPhone 4 32GB, iPhone 3GS 32GB, iPhone 2.5G 8GB
Reply
post #6 of 7
8/15/07 at 9:25am
Quote:
Originally Posted by Chopper3 View Post

Yes it is the 32-bit version as boot camp only deals with 32b versions afaik. Thanks for the tip-off anyway.

Boot-camp's *drivers* are 32bit, but all boot camp itself is is a mechanism for booting bios-based OSs on the Apple version of EFI and a pretty gui, I have XP x64 and Debian AMD64 booting perfectly fine on the Mac Pro I'm typing this one for example.
MBP (15, 2.33, 3GB,10.6/win/lin on 250GB)
MP (3,1 oct 2.8, 10GB. 10.6 on 4x1TB RAID10, Win/Lin on 1x2TB, 2407WFP on 1x5770 + 2xSamsung 910t on 1xGT120)
also a lot of other systems :-p
I met a...
Reply
MBP (15, 2.33, 3GB,10.6/win/lin on 250GB)
MP (3,1 oct 2.8, 10GB. 10.6 on 4x1TB RAID10, Win/Lin on 1x2TB, 2407WFP on 1x5770 + 2xSamsung 910t on 1xGT120)
also a lot of other systems :-p
I met a...
Reply
post #7 of 7
8/15/07 at 11:57am
Quote:
Originally Posted by palter View Post

Fusion support 64-bit guests. Parallels does not.

Cool, thanks for the info.
Reply
Reply
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Current Mac Hardware
AppleInsider › Forums › Mac Hardware › Current Mac Hardware › Windows only seeing 3Gb on a new 4Gb 24" iMac?