4GB of ram in Windows XP Pro 32Bit. A few questions for you guys...

[FusionZ06]

I've never run 4GB on a 32bit OS.

I've only run 4GB or higher on Server 2003 or 64Bit XP.

I know you have to do a PAE switch in the boot.ini

I then read after you do the PAE switch it will only show 3.5GB in Windows and the other 512MB will be dedicated to video memory?

Can anyone give me the run down on this.

Rig specs are in the sig...

[RyderOCZ]

The PAE switch doesn't do anything with Service Pack2, plus it is enabled by default even with 2GB installed.

XP with SP2 will recognize anywhere from 2.75 - 3.25GB of ram inside Windows. The number of Vid cards and how much ram is installed on them, other PCI-e cards, PCI cards, and onboard devices will affect this total.

[RX7boricua]

So what kind of numbers would we be talking about with a pair of 8800GTX 768MB video cards?

[aolforbroadband]

The PAE switch doesn't do anything with Service Pack2, plus it is enabled by default even with 2GB installed.

XP with SP2 will recognize anywhere from 2.75 - 3.25GB of ram inside Windows. The number of Vid cards and how much ram is installed on them, other PCI-e cards, PCI cards, and onboard devices will affect this total.

Is this why my 2GB of RAM only shows upas 1.98 in XP SP2? I have an Intel DG965WH mobo with onboard graphics(drivers not installed) but with a 7900GS. I want all that 0.02 of RAM back! :mad: :rolleyes:

[RyderOCZ]

So what kind of numbers would we be talking about with a pair of 8800GTX 768MB video cards?Probably in the 2.75 GB range...maybe less.

[Growly]

Does someone have any documentation or techincal papers on why this is, exactly?

[Malik]

I have the same problem - 4GB crucial AE in windows xp home sp2 - 2.75GB :(

[RyderOCZ]

In a 32-bit operating system....you can have 2^32 addresses, this equals 4GB (4294967296 bytes) of physical addresses that the OS can "see".

Every resource in the PC, has an address that must be "kept track of" (all the ram, all the drivers, devices, etc.) by the Operating system.

When you install 4GB of ram....guess what...you use all those addresses because you have that much ram...now, how do you keep track of everything else when you are at the limit?

Answer: you "forget" about some of the ram, so you have enough "room" to address everything.

The total amount available in each particular OS will depend on everything that is installed in your system, you can't necessarily compare to another system.

[XS Janus]

so much for 4gb ram on 32bit windows support. I hope game developers know this and realise it and keep in mind when they go wild developing new games.