4gig vs 2 gig ram

[- English -]

how much difference will there be when using 4 gig rather than 2 gig on DAOC lab. 8800gts card, usually duel logging. I can do it fine atm but i just fancied more ram

 

[Takhasis]

Blatently stolen () from bit-tech forums:

You will only ever be able to use the full four gigabytes with Windows XP 64-bit edition. The maximum addressable limit of any 32-bit operating system is 2^32 bytes, or about 4GB.

However, much of this is actually reserved. Modern computer systems use a technique called memory-mapped I/O, whereby CPU-addressable memory space is actually reserved as a means of communicating with I/O devices. These devices monitor the CPU's address bus and direct any operations performed on the MMIO area to their registers, effectively remapping the section into peripheral memory.

To save time and money, it is not actually possible to bank switch this area between memory and device addresses, so it's effectively unusable. However, if you're running a 64-bit processor and operating system, you can activate an option in your BIOS (usually PCI MMIO remapping or Remap Memory Hole Above 4G) that moves this MMIO area above 4GB to allow you to use the complete RAM capacity (note that you can activate this option without running a 64-bit OS, but it probably won't do anything).

There is a way to enable access to a bit more than normal on XP by modifying some configuration data (AFAIK it's the /PAE (physical address extension) switch), but ultimately you will never be able to access all of it unless you switch to XP64 or an equivalent Linux distribution.
__________________

PS, you didn't state what OS you were running

 

[- English -]

im using xp atm, although i do have 64bt vista.

 

[thergador]

the 8800 drivers(forceware) for vista suck at mo btw

and with xp32bit you will only address 3.6gig btw i have just got both vista and xp in 64bit for this reason got them both cheap as i got the OEM versions

os and windows xp sp1 see's all the ram its only SP2 that screwed up the ram but tbh sp1 is full of holes

 

[Killder]

I'd say twice as much

 

[Overdriven]

Well, as mentioned. XP/XP64 only supports XXX amount of RAM. But when going from 2GB to 4GB you'll notice a huge difference, especially when it comes to high performance/requirement apps.

(Ironically, Killder did give the best example... It's like 1024vs512.. Difference is obvious)