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reuvenbrom

macrumors newbie
Original poster
Jul 2, 2009
12
0
Hi,

I have a quad 2.66 Mac Pro with 3Gb RAM, and I just installed Windows 7 RC. When I go to 'system properties', it says I have 3Gb RAM but only 1.99Gb RAM usable. Why is this happening? Do I need to have a total of 4Gb RAM for it to be all recognized?

Any help would be appreciated. Thanks.
 
Did you download the 32bit or 64bit RC? It shouldn't matter anyways as you should be able to read up to 3gb with 32bit. 64bit shouldn't have that limitation...

I have a PC that won't boot with 4gb but works fine with 3x 1gb and 1x 256mb memory in mine. But only says 3gb are usuable. I have Windows 7 RC 32bit.
 
Windows 32bit can use 4GB of memory including your graphics cards. You wouldn't happen to have 2*1GB graphics cards?
 
I'm using the 32bit Windows 7 RC + 1xATI 4870 (512Mb RAM)

I don't understand why it should matter, since I only have 3Gb RAM.

Should I use the 64 bit version of Windows 7?
 
Because of the Mac Pro architecture, about 1GB disappears from your available 4 on Win 32bit.

Another ~1GB of adressing is also consumed by graphic memory and other stuff, leaving about 2GB for your RAM.



Win64 will give you no 4GB limit.
 
Because of the Mac Pro architecture, about 1GB disappears from your available 4 on Win 32bit.

Another ~1GB of adressing is also consumed by graphic memory and other stuff, leaving about 2GB for your RAM.

Win64 will give you no 4GB limit.

Spot on, Cindori.

It would be nice of Apple to say something. Just a brief technical
note would do.

Apple are wasting their customers time by keeping silent on such
matters.
 
I'm sure I saw a chart on here recently in image format that showed how the memory usage was divided up and why you lose the 2GB, but I haven't been able to find it.
 
Well Win7 is still free... just download the 64bit and burn to a disc and install. :D


Microsoft has a way to disable their software after they release the version you buy. So if they do that all the stuff you have in Windows won't work until you buy it. This has happened to me with their Office suite... :mad:
 
They ought to. This may come as a shock to some people,
but more of Apple's customers use Windows than OS X.

So Apple's stuff better play nicely with Window, or else :p
Unfortunately, this is a lesson they haven't learned very well. :( They did create Boot Camp, but have never developed any Windows drivers for their own RAID card. :rolleyes:
 
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