Member Avatar for chopficaro

im so confused! ive been told if i buy a 3gb 32bit systme i might have more available ram than if i buy a 4gb 32 bit systme! what?!

something to do with the drivers...

help! i need to understand! i need to buy a high end pc for starcraft 2 soon!

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There are a few different issues getting mixed together in the replies from , , and . Short, practical summary first: if you install 4 GB of RAM on a 32‑bit Windows machine you will often see less than 4 GB reported and available — that is normal and caused by how physical addresses are used by both RAM and devices. The technical detail explains the apparent contradiction.

Motherboards and PCI/AGP devices reserve regions of the 32‑bit physical address range for memory‑mapped I/O. Those reserved ranges sit inside the 4 GB address window, so part of the installed RAM cannot be mapped and therefore doesn’t show up to the OS. Some BIOSes expose a “Memory Remap” (or “Memory Hole Remapping”) option that lets a 64‑bit OS relocate that reserved window above 4 GB so all DIMMs can be used — on a 32‑bit OS that trick is useless.

Physical Address Extension (PAE) is another technology that lets a 32‑bit kernel map more than 4 GB of physical memory, but client versions of Windows historically don’t expose extra usable RAM to everyday apps because of driver and compatibility constraints; server SKUs and 64‑bit Windows are the reliable routes to full multi‑gig usage.

Practical advice if buying for gaming (StarCraft II era): pick a 64‑bit OS and verify 64‑bit drivers for GPU/sound/network if you want to fully use 4 GB or more. If you must stay on 32‑bit XP, installing 4 GB won’t harm anything — expect the OS to report roughly 3.0–3.5 GB usable depending on motherboard/GPU — and check BIOS and Windows’ System Information to see how memory is being mapped.

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Member Avatar for UrbanKhoja

For a while Vista was unable to properly read 4Gb RAM, but this should have been fixed in recent updates though?

To my knowledge systems prefer even numbers when it comes to RAM rather than odd ones, I.e 32, 64, 128, 256, 512 etc. So not sure if you'll get the most out of 3Gb.

Dazza :cool:

Member Avatar for jbennet

no no no

it will never be fixed

people just assume it was fixed in vista sp1 because MS changed it to now read the total ram, not the total available ram.

its due to the fact that 32 bit systems cant address that much memory (the memory addresses are physically too long to fit in the CPUs registers)

all 32 bit oses cannot address more than 4gb ram. 64 bit systems can use a hell of a lot more .

Also, 4gb of ram on windows x32 is a waste, because the workstaion versions only allow running apps to use up to a total of 2gb (server versions allow up to 3gb)

Member Avatar for dise652

seems help a lot

Member Avatar for chopficaro

some people say they can handle 4gb, some say 3, some say 2.
still confused. i want to get as much memory as i can on 32bit windows xp. which version of windows xp should i download? how much ram is able to be used? if i add more than that, can the devices use the extra memory?

Member Avatar for jbennet

4gb max
2gb max can be used by running programs in a standard configuration

which version of windows xp should i download

i hope you dont imply that you are pirating it !

Member Avatar for bobbyraw

4Gb of ram on windows is a waste and as for which version of windows you should use depends on the processor you have.

Member Avatar for binoj_daniel

You can defintely benefit by adding 4GB RAM on your pc running Windows XP.
There is a switch called /3GB which can be used to maximize memory address space usage for user processes.

Please read this kb article for more details.
3GB switch best works on servers.

Let me know if you need more info.

Member Avatar for jbennet

most processes wont use the memory /3gb gives them , only ones i know of are the MS server producvts and some CAD/CAM software

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