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XP only recognizing 3GB of my 4GB ram

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September 7, 2007 1:44:10 PM

I've seen this prob reported everywhere over the last 12 months. I recently popped in another 2GB or ram cause it was too cheap to pass up. (OCZ = $64 for 2GB, my word).

Anyway, going to do some research now but wanted to ask here first. I know its got something to do with XP not being programmed to handle more than 2GB etc. Cant remember exactly. Any thoughts?

I'll post what I dig up.
September 7, 2007 1:52:05 PM

Is this accurate:

http://www.tomshardware.com/forum/231766-45-windowsxp-r...
The solution is easy, open up your boot.ini file in the root of your system drive. At the end of the line for your XP installation, add "/PAE" without the quotes. This enabled the physical address extensions which will allow you to use up to 4GB of memory (the upper limit in XP Pro).
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September 7, 2007 2:09:04 PM

Explanation??

Microsoft Windows XP Professional, designed as a 32-bit OS, supports an address range of up to 4 GB for virtual memory addresses and up to 4 GB for physical memory addresses. Because the physical memory addresses are sub-divided to manage both the computer’s PCI memory address range (also known as MMIO) and RAM, the amount of available RAM is always less than 4 GB. The memory addresses starting down from 4 GB are used for things like the BIOS, IO cards, networking, PCI hubs, bus bridges, PCI-Express, and video/graphics cards. The BIOS takes up about 512 KB starting from the very top address. Then each of the other items mentioned are allocated address ranges below the BIOS range. The largest block of addresses is allocated for today’s high performance graphics cards which need addresses for at least the amount of memory on the graphics card. The net result is that a high performance x86-based computer may allocate 512 MB to more than 1 GB for the PCI memory address range before any RAM (physical user memory) addresses are allocated. RAM starts from address 0. The BIOS allocates RAM from 0 up to the bottom of the PCI memory addresses mentioned above, typically limiting available RAM to between 3 GB and 3.4 GB.

http://www.dslreports.com/forum/r18323522-ASUS-P5W-DH-d...

Does this mean that the 4GB is being used (even if one goes towards the PCI)?, and that XP can only access 3GB? Is the performance gain worth the $64?
September 7, 2007 2:27:25 PM

I really shouldn't tell it to you in a polite way, yet, i can't stop minding my manners. I strongly suggest you use the search function or just look around the forum a little. This topic, the 4GB barrier of the 32 bit operating system, has been discussed over and over for the last few months. There are dozens of threads that all come to the very same conclusions. Now do the right thing and search a little instead of posting and hoping someone will serve the answer on a silver tablet. :) 
September 7, 2007 2:32:03 PM

fishboi said:
Is this accurate:

http://www.tomshardware.com/forum/231766-45-windowsxp-r...
The solution is easy, open up your boot.ini file in the root of your system drive. At the end of the line for your XP installation, add "/PAE" without the quotes. This enabled the physical address extensions which will allow you to use up to 4GB of memory (the upper limit in XP Pro).


No. This will not help you in xp 32. PAE is only for a server OS and for certain apps, such as SQL server, which run on server OS. Moreover, IIRC, PAE will only allot more of the 'available' RAM to an application, stealing some from the OS.

PS I could be a little foggy on the details of PAE but I'm pretty darn sure it's useless to XP 32.

Is having the extra gig worth it in XP? Well for such a cheap price I'd say sure, why not, but then again I seriously doubt XP can really make use of any more than 2 gig, perhaps with the exception of some few apps. My board maker, ASUS, actually reccomends not using more than 2 gig for XP. I installed it anyway and now I get some odd sound problem that only happens about every other boot. So for XP my advice is stick to 2 gig. Vista 32 may do a better job of using more RAM however.

Of course you can go to a 64 bit version of Vista or XP and get all your 4 gig used.
September 7, 2007 2:36:35 PM

Must... kill... this... thread.
September 7, 2007 2:44:48 PM

rodney_ws said:
Must... kill... this... thread.


LOL. There's a lot more coming brother! RAM is cheap and lots of people are just getting on to this. I bet it's gonna take a while for this to disseminate. It's confusing to boot.
September 7, 2007 2:58:56 PM

Slobogob said:
I really shouldn't tell it to you in a polite way, yet, i can't stop minding my manners. I strongly suggest you use the search function or just look around the forum a little. This topic, the 4GB barrier of the 32 bit operating system, has been discussed over and over for the last few months. There are dozens of threads that all come to the very same conclusions. Now do the right thing and search a little instead of posting and hoping someone will serve the answer on a silver tablet. :) 


HalleFREAKINlujah.

just how many times does this have to be asked and answered?

next time all the responses should be GBYA
GOOGLE BEFORE YOU ASK
September 7, 2007 3:00:53 PM

rodney_ws said:
Must... kill... this... thread.


Maybe we could make it look like an accident.

like the thread was drunk... walking along a ledge... and just happened to plummit 300 feet to the rocky ground below... no no, it wasn't pushed...

a b } Memory
September 7, 2007 4:17:42 PM

Did you waste $64, hell no when its vista time down the road you have the ram you need. In the meantime you still have 1gig extra on your system.

PAE(Physical Address Extension). was a intel way to give server OS's access to there much needed ram. It does nothing for XP but server class systems can use it to get massive amounts of ram to work.

Now to add to the confusion


Current system with 4 gigs of ram and a 8800GTX....Looks to make sense 768 megs off of 4 gigs gives me 3.25.

Next

Same system with a 4meg S3 Virge DX card. not this does not add up at all....

Last

Both cards at the same time.

Does not seem to be direct with all onboard ram either or the 4meg card would not take so much...
Anonymous
a b } Memory
March 22, 2011 10:32:44 AM

Slobogob said:
I really shouldn't tell it to you in a polite way, yet, i can't stop minding my manners. I strongly suggest you use the search function or just look around the forum a little. This topic, the 4GB barrier of the 32 bit operating system, has been discussed over and over for the last few months. There are dozens of threads that all come to the very same conclusions. Now do the right thing and search a little instead of posting and hoping someone will serve the answer on a silver tablet. :) 



Well your user name says it all! The reason we have a forum is to allow people to raise valid questions and queries. Now some people enjoy searching through lots of entries and have plenty of time to do this. Others may not understand the system fully and may not be able to use it to its full extent. As for the comment of use the search and not wait for someone to had it to you on a SILVER PLATTER. Well I can use some of that comment, PRATS, like you should stay out of forums if you cannot be bothered to assist people and only use the forums to throw abuse at peoples enquiries.
!