bornking

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Jul 10, 2006
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I recently upgraded my ram.
I had 2 sticks of 1024 Twin2xMX2 corsair at 4-4-4-12 800mhz DDR2, and added another 2 sticks for a total of 4gb.
I initially had it working fine but after a few days (NO OVERCLOCKING) my mobo (striker extreme) gave me the dreaded 3 beeps.

I had the timings at 4-4-4-12 and reset them to auto and they were read at 5-5-5-18. I made sure to get the right model (4-4-4-12) and CPU-z told me to change the voltage to 2.1 from 1.8. I did so and everything is now at 4-4-4-12.

Ok getting back on topic. Windows XP pro 32 (allupdates installes including .net 2.0) tells me I have 2.55 GB of ram...huh?

ANy ideas why?

I also have vista ultimate 64 which reads all 4 gb.

Please help.
 

stemnin

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Dec 28, 2006
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You have 2 8800GTX in SLi?

32 bit OS has limitations, can only see/address? 4GB total memory, this includes video cards and other things.
 

duxducis

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in Windows XP 32bit max u can get is 3.5GB but actual number will wary from ~2.5-3.5GB depending on your hardware
specially SLI will eat your ram, and other things plugged into PCI slots on your computer

to maybe get more ram go bios and disable everything you don't need (like floppy, ports, sound, nic) devices that use PCI Bus will reserve ram for them selfs

and there is no patch, no work around for this u get what u get,
(some motherboard have special future for when u use sli and 4GB ram to reserve less)

also for me it was easy to change timings on 2x 1GB sticks of ram, but when added 2 more system can only boot up on default settings and only on auto :(

there is no benefit from 4GB on windows xp, (like gaming and regular use) the only reason i have 4gb because i use Paint shop, and create RAM drive for image editing.

the only good reason is to use 4x 512MB sticks(if u have 4 memory banks), in my test with 2 banks used i get like 8gb/sec but with 4 sticks in 8.5gb/sec just for adding them
 

HYST3R

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remove one of your 1gb ram sticks and see what you come out with, dux is right, 32bit OS's cant access 4gb of ram. 64 bit on the other hand can access alot more than jsut 4gb, thats why your vista sees it jsut fine.
 

LukeBird

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I'm about to go to 4Gb RAM in XP Pro 32-bit.
I run a GTX also and know its going to page anything from approx 3Gb.
Just wanted to know about the timings, I have 2x1Gb Corsair PC6400 @ 4-4-4-12 @2.0V.
This thing with CPU-Z, this page-
cpuzramos7.jpg

is this the suggested timings & voltage? Am I going to have to use different timings when I go to 4Gb?
 

smitten

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Nov 19, 2007
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Because of too many poorly written drivers, Microsoft chose to limit the address space in SP2 to exactly 4G. And as others have said, you need to fit both RAM and other hardware devices in this limited address space