So I bought an additional 2GB of RAM today, hoping to expand my RAM to a total of 4GB. Unfortunately no matter what I do, I can't get XP Pro to recognize more than 2.75GB of RAM. I've modified the boot.ini file with the /3GB switch, and I've made sure that PAE is enabled, but still no such luck. My motherboard can see all 4GB, and if I go to System Information it says I have physical memory of 4GB, but if you go to My Computer>>Properties it says I only have 2.75GB. Anyone have ideas? System Specs: EVGA 122-CK-NF68-A1 680i Motherboard Intel Core 2 Duo E6600 2 x 1GB Corsair XMS2 PC6400 2 x 1GB PNY Optima PC5300 (The RAM I purchased for super cheap at my work). Geforce 7600GT 320GB WD SATA HDD Everything is at default timings at the moment.
yup XP has a 3 GB limit however 256 of that is used to access you video card. hence the 2.75. Vista can do the full boona but it's slower than a week in the jail. The Bear.
Wow! This thread could not have been better timed! I was going to go to the local PC shop in a couple of hours and buy 4 Gigglebobs of RAM to upgrade my machine tonight (currently running 1 Gigglebob). Lucky I saw this, eh? I'd better double check a few things before I part with my cash.
Sorry that should have read 4gb limit Is it XP pro or home? If it's home then that is why you aren't seeing the full 4. It varies exactly how much you see by the devices you have attached. The Bear.
I'm using XP Pro SP2. I've read online through Microsoft and various other websites that you can push XP Pro to a max of 4GB but so far I haven't had luck with that. I also have a dedicated video card so why would Windows still be using part of my RAM? Microsoft says all you have to do is add the /3GB switch and/or use PAE and you should have access to a full 4GB. (I would be happy with just under that amount too, it's this 2.75 that's making me angry).
I am afraid that's simply not true, shame on you for believing microshaft. Do you really need 4gb? The Bear.
Ad McG said:- Ah hah! That's the point. I was jumping in without really thinking . I'm settling for upgrading to 3 Gigglebobs for now (a one meg stick and a new two meg stick).
My user manual for my Dell XPS system says I can have a maximum 4GB with Windows XP Pro or 8GB with XP Pro 64bit version running with an Intel Core 2 Duo CPU. It doesn't say anything about doing any modifications to boot.ini or anything else. It's meant to be plug it in and go play Doom 3 on stupidly high settings. Even if you have a dedicated video card Windows XP still uses some system RAM for display functions. It has something to do with the device independent bitmap image. However this shouldn't have any effect on what My Computer shows as installed RAM. When looking at MY Computer > Properties after the part that says 2.00GB of RAM (which is what I currently have) it says Physical Address Extension. I don't know if that's significant. Does your system read the same. If not it might be. I've never seen it on any other system. Maybe you're PC just can't physically handle the full 4GB. I'd say your next step is to check for BIOS updates for the system board.
I've done some reading up on this. So far as I can figure the /3GB switch applies to virtual memory space and not to physical RAM in the machine. Virtual memory is a special file on the hard drive sometimes referred to as the page file. Using the /3GB switch will do nothing to make Windows see you're full 4GB of RAM. What it does do is restrict the kernal to 1GB of virtual address space and then allocate another 2GB to user applications. Giving you 3GB of virtual memory. Read that as in Windows uses 3GB of your hard drive space as a scratch pad. The reason Windows has a 2GB page file or virtual memory is because Windows likes to have at least half as much virtual memory to play with as there is actual physical memory. This is the way it's been with Windows since 3.1. I'm also not convinced you need the PAE feature. This is for addressing memory above 4GB so far as I can figure out. Which Windows XP Pro doesn't support in 32bit mode. To get more than 4GB you'd need to get the 64 bit version of XP Pro. The PAE feature is actually intended for Windows 2003 server and the like. Not a desktop PC. Although I could be wrong 'cause I just realised PAE probably means Physical Address Extension. I'm pretty much convinced this is an issue with your system board and it's ability to support the full 4GB. Check the BIOS settings. Make sure the BIOS is seeing the full 4GB or near as makes no difference. It's also worth noting PAE is an Intel feature and not a Microsoft Windows feature. http://www.microsoft.com/whdc/system/platform/server/PAE/PAEmem.mspx http://www.microsoft.com/whdc/system/platform/server/PAE/pae_os.mspx http://support.microsoft.com/kb/833721
http://support.microsoft.com/kb/929605 http://evga.com/support/knowledgebase/ Ok I found the above article via the EVGA knowledge base. It seems that when Microsoft claimed Windows XP Pro could support 4GB of memory they were talking about total memory address space and not just your system RAM. That being the case your PC will never be able to access the full 4GB of RAM because every hardware component needs it's own address space. To access the full 4GB of system memory your PCs system board chip set needs to support at least an 8GB address space and meet the other requirements in the link above.
http://nvidia.custhelp.com/cgi-bin/...F90ZXh0PTRHQiBXaW5kb3dzIFhQ&p_li=&p_topview=1 I checked the nvidia site since it's their chipset that's at fault here. The above link is what nvidia have to say about the problem. Which although true is a bit of a cop-out since other since other chipset manufacturers seem to have a work around. In short your motherboard can't handle a full 4GB of RAM and have everything else plugged in at the same time. Which is a bit useless. Unless you upgrade to a 64 bit OS.
Thanks for all your hard work Aikiwolfie. I flashed my BIOS to the latest version and my max for RAM is 8GB. I ended up figuring this was a lost cause and returned the RAM last night, lol. Underneath My Computer>>Properties it does say Physical Address Extension. I'm just gonna wait until I'm ready to switch over to 64-bit Vista. Thanks again though Aikiwolfie.
no problem. My head nearly exploded trying to read all the Microsoft crap. Been too long since I did this stuff. I'm old
A 32-bit OS is always going to have issues with RAM above 2GB. I'd recomend switching to Linux/BSD/Solaris to ensure that it works =) And for anyone else with the issue, since KageAkuma's was solved, also check your chipset. Even though the processor is 64-bit (the proc can handle up to something like 16 exabytes) the system bus could be 32 bit (remember the Intel 80486? 32bit proc with a 16 bit bus).
The problems not with the OS. It's the way specs are advertised these days. People are told a system can handle 4GB of RAM so they expect the full 4GB. The trouble is the marketing people don't explain to user that a portion of that 4GB address space gets eaten up by system devices like graphics cards and sound cards etc. Most new PCs today will have a Core 2 Duo CPU. This is a 64-bit CPU which means it has an 8GB address space. However 32-bit OSs like Windows XP and Windows Vista or even 32-bit Linux won't get the full use out of 4GB of RAM purely because they aren't designed to work with 64-bit architecture and therefore can't take advantage of the extra address space without some fancy work around. If you want more than 2GB of RAM on a 32-bit system I'd settle for 3GB as the target. Go for a configuration of 2x1024MB + 2x512MB modules. For Windows you might also want to upgrade to Vista.
Eww Vista...... Go with a free OS, like *BSD, Linux, Solaris, etc. They tend to work better faster longer etc. Or get a Mac. Or get Windows XP 64-bit edition (for AMD64/EM64T, not IA-64). Any of them is an upgrade compared to Vista.
Well I'm guessing KageAkuma wants the extra RAM for better games performance. Which puts Linux, BSD and Solaris not to mention Mac OSX out of the running. Otherwise I'd advise him to forget the RAM upgrade all together and switch to Ubuntu. Microsoft won't be supporting XP for much longer so any XP upgrades are going to be a relatively expensive investment. Windows tends to stabilise with numerous service packs. Vista will be no exception here. SP1 is due out sometime 2008 I think?
Stability is not why I recommend against Vista. Vista, while flashy, has obnoxious resource management, and, as admitted by MS, cannot even play mp3's and browse the internet at the same time.
