[Spewpuke]

Anyone had trouble with Vista Ultimate not reading BIOS physical memory. I have Asus P5B deluxe, E6750, GeForce 8500 GT 512, and 2x2gb ddr2. Bios has been updated, and reads 4096 Ram, Vista only sees 2048, I can remove/swap ram modules and it still only sees 2048, it just does not read 2nd module. Ram Modules are in slot a1 and a2 for dual channel. I'm out of ideas short of trying to reinstall Vista. Maybe install Linux to see if it reads the BIOS, I dunno.

Anyone?

[lunat1k]

There is a problem with the ACPI in vista that will only reads 2 gig of ram, check with your Motherboard manufacture for a bios update.also do not use the 3rd stick to get 3 gigs of ram to show as it will only cause your system to crash.

There is a fix for this in the upcomming? SP1 from microsoft that should fix this problem.

[Elvandil]

I'm afraid that Vista 32-bit can not ever use 4 GB's of RAM. There will be no update that can fix that "problem". Any 32-bit operating system has only 2^32 memory addresses available, and that means all addresses, including that of Video memory, BIOS ROM's, and caches. So even though Vista can access 4 GB's maximum in theory, because of the other addresses already used, the maximum it can ever use is probably around 3.5 GB's for most machines.

In ordeer to use the 4 gigs, you'll need a 64-bit operating system.

http://news.softpedia.com/news/32-bi...AM-49647.shtml

[Spewpuke]

I don't think you guys follow me, My Bios says 4096. Vista says 2047, regardless of having 1 - 2gb module or 2 - 2gb modules.

If you add the 512 Mb ram from Video, and the way vista can only address 4096 KB, this still leaves me a 1024 that is somewhere in ether....

Vista, from what I have read should be able to address 3.5GB but it is not. It is only reconizing 2048.

Thanks for your links though.

[lunat1k]

Have you setup the memory in the bios yet?



Some boards require you to add the memory into there.

[Elvandil]

The "other" memory is mapped before the system RAM is mapped. It starts with the first chip, maps that, and then checks to see whether it can map the second. It your case, it can't, so it ignores the second chip completely. If you replace the second with a 1 GB and, if you have a third slot, put in a 512, then you will most probably see the 3.5 GBs. Some BIOS simply won't even attempt to map "part" of a stick of memory.

Depending on your BIOS, you may be able to activate "Physical Address Extension" in order to put the full 4 GB to use (just as Server 2003 can "see" the full 4 GB).

http://blogs.msdn.com/oldnewthing/ar...14/699521.aspx
How To Enable More Than 3.5 GB Of Memory In Windows Vista

[Spewpuke]

You were exactly right, Vista was ignoring the second module, I installed 64 bit Vista, and there is no problem....

Thanks for your help guys.

[Elvandil]

That's one way to do it. Congrats!

It isn't really Vista that is the problem, it's those darned laws of physics and mathematics .

You can mark your own threads "solved" using the Thread Tools at the top of the page.

[trakker]

I am having a VERY similar problem BUT I am NOT running 2 x 2GB sticks, I am (was) running 4 x 1 GB sticks and Vista was only reporting 2047MB. I've since removed one of the sticks and still Vista is only reporting 2047MB. With three sticks installed, BIOS reports 3072MB on startup and the RAM has all been tested good but Vista still only reports 2047MB.

I did try the 64 bit version of Vista when I had all four sticks installed and yes, it did report 4096MB of RAM however when I reverted back to the 32 bit version once again Vista started reporting only 2047MB. I've tried the sticks in every slot combination possible with no difference... BIOS see's full amount, Vista only see's 2.00GB.

Any ideas (other than installing the 64 bit version)?