Any RAM over 4GB is useless in Windows XP and Vista?

[ljCharlie]

I just purchased a laptop that has 4GB of RAM in there and it only show up in the System Properties\General as 3.37GB instead of 4GB. When I called HP, the tech support says that Windows XP or Vista will not utilize anything that is over 3.37GB of RAM unless the operating is 64bit. Is this true? I've never heard such thing? Is he giving me the crap on this?

[Kasturi]

Yup, this is true

and no he is not giving you crap

[ljCharlie]

Okay, then why do pc makers claimed that their pc can handle 12GB or so when it is useless after 3GB.

[perkster]

the PC can handle that, just your operating system cannot. you have a 32 bit OS which has enough memory addresses for 4gb but becuase your hardware takes some of those addresses the actual amount being used for your RAM is about 3.2gb. If you want to ultilise your 4gb ram or more if you fancy you need to upgrade yoru OS to a 64 bit version, there are 64 bit versions of XP and vista, but the XP one has more issues than the vista one.

[Statica]

Originally Posted by ljCharlie Okay, then why do pc makers claimed that their pc can handle 12GB or so when it is useless after 3GB.

There have always been situations in the tech world where a particular limitation has shot down the usefulness of something else. For example hard drive sizes and BIOS limitations have historically been at odds. Mobo manufacturers have provided a way to utilize more RAM slots, provided the software isn't crippled. And it isn't just a Windows only thing, a lot of OS' have similar limitations. With Linux however, given it's modular nature, it is possible to recompile the kernel to make use of the newer processors' extensions (PAE) to see more RAM... at a performance cost.
The solution is to use a 64bit OS, Vista - as mentioned - fares a lot better than XP 64bit.

[ljCharlie]

Thanks! To use 64bit vista, that means the CPU will have to support or made for 64bit OS, correct?

Well, thanks for your input.

[Statica]

Yes but most new CPUs are. What are the specs of your laptop?

[perkster]

most modern day CPUs are compatible with 64 bit, but yes your hardware would need to be compatible. If you let us know your specs we can tell you if yoru computer is suitable for a 64 bit OS.

if you have an old processor you probably wont get much benefit from 4gb ram over 2gb ram anyway since the processor is likely more of a bottleneck.

[ljCharlie]

Thanks! I just got the new laptop yesterday with Intel Centrino core 2 duo.

[perkster]

then you will have no problems, did you buy XP or vista, i think with vista sometimes you get both versions and can pick which to install, or you can get them to send you a 64 bit version for free, sure i heard that somewhere.

[mairving]

Installing the 64 bit version of Windows will not only be a waste of time but you won't get a performance gain currently and may even take a hit. The only advantage will be that Windows will be able to see that extra little bit of RAM that never gets used. Drivers for 64 bit versions are currently the biggest problem. Not much of anything is optimized for 64 bit. In a few years maybe but not now.

I would personally stick with the version that you have.

[Statica]

What are you running that requires that 0.63MB of RAM? Most apps are going to be quite happy with 3+GB that you're using. Also consider that you're going to take a performance hit moving up to Vista (64 or 32bit) and so any gains you think will come of seeing the full 4GB of RAM will be lost in the upgrade to Vista.

[glc]

I do builds with 4gb of ram with XP 32 - so it only sees 3.25 gigs? Big deal - ram is so cheap it really doesn't matter, these machines use all they can. I'd rather run with underutilized 4 gb in dual channel than 3 gb in single channel.

[ljCharlie]

Thanks for all your input. I was just curious why it's not using the full 4GB. We custome order this laptop for using it with Adobe CS3. Yes, I absolutely agree that upgrade to Vista right now is a bad idea. I've heard so many problems with Vista...I've actually have one machine upgraded to Vista and I arleady uninstall it because of the amount of problems and drives issue with it.