32 bit 4GB RAM only?

No it doesn't, you can't make a 32bit system address more than 4GB
PAE is not the same thing.

PAE is exactly how you can make a 32bit system address >4GB.

MASQUERAID, Scissors85, I think i have seen some 32 bit vista machines sold with 6 GB ram.. what is the deal there?

@25112 That is what we call a "Marketing Scheme". I myself saw 4GB machines that were pre-installed with 32-bit. This happened quite often when 64-bit was first becoming the norm. Nowadays though since everything sold is basically 64-bit it isn't a big deal. But yea I used to see Vista 32-bit with 4GB RAm and I would just laugh...

I've no idea, Vista by default has PAE switched on but there is a system limit in 32bit XP, Vista and Windows 7 which means even if PAE is enabled no physical memory beyond 2^32 can be accessed.

BTW Apologies to Papertrip - I was too focused on Windows clients - yes server systems can use PAE to map to a larger physical memory capacity. But with 64bit hardware so widely available there's little reason to do this.  For Windows clients I stay with my original answer.

Actually all of the info I have provided thus far applies to certain versions of Windows as well, granted only to Server grade versions.

http://en.wikipedia.org/wiki/Physical_Address_Extension#Microsoft_Windows

I was told 32 bt machine can use only 4gb ram. and anything more is not possible or is waster..

My original answer is completely correct.  If you have a 32bit system using PAE, then having >4GB is not a waste.

But with 64bit hardware so widely available there's little reason to do this.

With 64bit hardware, PAE is irrelevant and unnecessary.  Yes 64bit hardware is widely available now, but this question is about 32bit.

For Windows clients I stay with my original answer.

But your original answer is incorrect.

yes server systems can use PAE to map to a larger physical memory capacity

That, however, is correct.

OK, how does a 32-bit Windows Client system access >4GB with PAE?

I assume you mean versions of Windows that are not Server edition?  As I said in my last comment, PAE is only supported on Server editions.

PAE is supported on Windows client systems as well as server (from XP)  but there is a 4GB system limit on maximum available memory.

So the answer is 'Yes' if you're putting XP, Vista or Windows 7 on

and

'No', if you're putting a Windows server system on (except W2K3 Standard which still has a system limit of 4GB)

http://msdn.microsoft.com/en-us/library/aa366796.aspx

Fair enough.

My original answer is the correct answer for this particular question, it was only asked about a "32 bit machine", OS was not mentioned.

Absolutely - it was an interesting journey though.
2am here so time to go :)

Good night :)

Thanks, I've certainly learnt a lot from this thread.

Thanks, I've certainly learnt a lot from this thread.

The best part of EE for experts aside from the shirts ;)

There are shirts??

:D

thanks very much