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question about 4GB limit for 32bit OS

1212 Views 3 Replies 4 Participants Last post by  greenbrucelee
I have built my own custom PC in the past. At the time, I was new to it & after some research, I understood that 4GB is the limit for 32bit operating systems. I therefore ordered 4GB of memory. However, after installing my WinXP Professional, it apparently was only seeing 2.87GB of the installed 4GB of memory. I then went ahead reformatted the drive and installed a 64bit version of XP. It did see all 4GB & all is working good. I ocasionally run into some compatibility issues, but that is due to the 64bit XP that is installed.

I am looking to build another new PC. It will be for basic needs and nothing real demanding (like gaming). Therefore, I would like to put a 32bit version of XP Professional on it so I can get better compatibility. I am looking at getting an Asus motherboard (model #P7H55-M PRO), but am debating on how much memory to buy.

If I buy 4GB, will it most likely get bumped down to just under 3GB like before? Or could I get more out of it with this board? It takes DDR3 memory and I have heard it depends on each board on how close to 4GB it will use. Is there any way of knowing or is it just a guessing game. I also have a 32bit version of Win7 Professional that I thought I would like to maybe install (as a dual boot system) so I can play around with that some more here.

Now, I thought about getting just 3GB of memory for now for this board. The price difference is about $20. I would have to get a 2GB and a 1GB chip. I figured if the 32bit XP only sees about 3GB of memory anyway, why not just buy that much. I can always get more later if I want to upgrade to Win7 64bit.

Any thoughts or suggestions concerning this situation & maybe the best way to approach it?
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I don't have additional information, but can just confirm that you are right that any 32-bit operating system will not see the full 4GB. I have an Intel Atom net-top computer with 4Gb installed, it will only work with Windows 7 32-bit, not 64-bit, as this processor is not 64-bit compatible. Windows sees about three and a bit GB.

In real terms if you buy that fourth gigabyte, you are really getting a lesser amount for your money, as long as you are running 32-bit. Yet, I don't think there are many situations where the PC would perform much better or worse depending on whether it had that last fraction of a gigabyte.

Financially, if you're going to upgrade to a 64-bit OS in the future, and upgrading from 3 to 4 GB, you will be paying now for 1GB and later another 2GB chip to replace it. If by then the cost of a 2GB chip has come down to what a 1Gb chip is now , then you have lost nothing. If the 2GB chip is still expensive, then it would have been better to buy the full amount in the first place. (I hope this logic makes sense)

You may even end up wanting 6 or 8GB in the future, which would mean buying new chips anyway. Personally, I like the argument "I can always get more later".
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It just depends on your preference. I've always ran 64-bit operating systems, and i've got 4 GB or ram.
windows will only use upto 3.5GB RAM when running a 32bit OS because it cant see any more than that due to address limitations.

If your running integrated graphics (i.e onboard) then that will use some of the ram.

As for how much ram you will need running 2GB in dual chanel is better and faster than running 3GB which will have to run in single channel. Whereas 4GB (2x2GB) is better still even though windows can only use upto 3.5GB of it.

However running 4x1GB will fill up the slots and filling all the slots can cause voltage issues and stability problems so better to have 2x2GB if you want 4GB.

I never run 64bit OS as there is no need, unless your doing high end video production or graphic intensive drawing apps then no other app or game will use more than about 3GB RAM anyway.

If I remember correctly the most intesive games out there at the minute use less than 3GB RAM.
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