MacPro1,1 (c.2006) 16GB RAM Upgrade Needs 64bit Win 7 OS?

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GreatestOne

Limp Gawd
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May 15, 2005
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Hey guys.... client has a 32bit Vista running on his MacPro1,1 right now, had 1GB RAM, got him 16GB because he wanted to stay with that computer. However it only shows 8GB, and reminded me of the times Windows always showed less RAM when it was 32bit.

So would this be as simple as upgrading to like 64bit Win 7 and it will use all 16GB?

Thanks!
 
You can't just "upgrade" to a 64bit OS from a 32bit OS.

You have to re-install from scratch.
 
GreatestOne said:
Hey guys.... client has a 32bit Vista running on his MacPro1,1 right now, had 1GB RAM, got him 16GB because he wanted to stay with that computer. However it only shows 8GB, and reminded me of the times Windows always showed less RAM when it was 32bit.

So would this be as simple as upgrading to like 64bit Win 7 and it will use all 16GB?

Thanks!
Click to expand...

Yes, you do have to use a 64 bit install of Windows to use more than 4GB of RAM.

You said 8GB of RAM is already showing not 4GB. Where is 8GB showing up? It sure as hell wouldn't show while in Vista 32bit. If its in the Bios (or Mac equivalent) then you have some other issues. Does that computer even allow 16 GB to be installed? Did you buy RAM that was compatible with it?
 
CaptNumbNutz said:
Yes, you do have to use a 64 bit install of Windows to use more than 4GB of RAM.

You said 8GB of RAM is already showing not 4GB. Where is 8GB showing up? It sure as hell wouldn't show while in Vista 32bit. If its in the Bios (or Mac equivalent) then you have some other issues. Does that computer even allow 16 GB to be installed? Did you buy RAM that was compatible with it?
Click to expand...

Actually some guy who knows macs said this is 32bit hardware and wont support any 64bit OS... dang that sucks... might just have to return the other 8GB. I read somewhere someone messing with a part that could make it compatible with 64bit OS but I cant remember what it was.

It shows 8GB in Computer properties.
 
GreatestOne said:
Actually some guy who knows macs said this is 32bit hardware and wont support any 64bit OS... dang that sucks... might just have to return the other 8GB. I read somewhere someone messing with a part that could make it compatible with 64bit OS but I cant remember what it was.

It shows 8GB in Computer properties.
Click to expand...

Yeah... that guy doesn't know Macs.

It's a 64bit machine.
 
All Mac Pros are 64-bit machines.

The early ones only have 32-bit EFI firmware, which limits the ability to boot 64-bit OS X kernel, but Windows bootloader doesn't care. 64-bit Windows will run on any Mac Pro.

The 8 GB issue is interesting - even 32-bit Windows 7 or 8 will report the full amount of RAM installed, but not let you use all of it, so the fact that it's only showing half the RAM is potentially worrying.
 
If he's lived with one gig until now, I wouldn't worry about missing 8 lol.


16 is massive overkill.
 
IIRC, the first generation of MacBook Pros all had "Core Duo" CPUs

Again IIRC, Core Duo chips have something, (I think it was called EMM64) that allowed them to use more than 4GB of RAM, (this was a technology Intel developed for servers, long before there was real need for a full 64-bit chip) The Core Duo does NOT have a full set of 64-bit registers, and cannot execute x64 code, but an EMM64 supported 32-bit OS can give a 32-bit program its own 4GB of RAM if it's avalable.

Often BIOSes have limitations on how many memory chips they can address, and the published "Limits" are based on what the manufacturer can get a hold of to test with. As denser chips come out, they may or may not work properly.

That being said, as someone who is running a unibody (Core 2 Duo) with 4 GB of RAM, I can say that even 4GB is plenty.
 
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If he's running 32bit Windows, he shouldn't see 8GB of ram, he should see 4GB. 64 bit re-install will fix that.

Otherwise, test the ram, verify it's all actually good ram.
 
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