4GB memory showing as 3GB

Hi,

So decided to add more memory to my pc and have 4GB instead 2GB. However pc was showing 3GB after installation and an online search on it suggested it is because it is 32 bit xp.

My question is, is there any point in having 4GB instead install when only 3GB is recognised? In that case is it better to just have 3GB in total installed?

Cheers

Whether 3 or 4 physically installed the computer will perform about the same. 3GB would be a little cheaper than 4GB but if you already have the 4GB installed it won't be any worse than having 3GB.

Read more about this issue here: http://blogs.msdn.com/b/hiltonl/archive/2007/04/13/t...

It's some BIOS quirk on 32 bit Operating Systems. To get around it, you'll most likely have to move on up to a 64 bit version of Windows (eg. Windows 7/8).

Thanks, think will have 3GB installed and use the extra 1GB in a friends pc.

Depending on the motherboard, you might get better performance from not having all the slots in use. Equally, if you have dual channel memory, and you don't use the slots in pairs (2 or 4) you might get less performance. Suck it and see really.

Try:

http://www.maxxpi.net/pages/downloads/maxxpisup2---p...

It's a very simple test which returns a K/sec result. The larger the test, the slower it gets etc. Try with 2, 3 and 4 sticks to see what's best. If no diff, pick whatever suits you.

You can usually get a raft of improvements from your PC setup if you look more into tweaking (reducing bloat, overheads, disabling unecessary services etc.)

Seeing this post made me check my computers (32bit xp) today because upgraded them from 2GB memory to 4GB memory recently. From what you folks are saying i should have saved my money and added just an extra GB in each machine since they will only be using 3GB and not the 4GB installed. This is a rip-off.

It depends on the graphics memory in use. Some machines with low memory on graphics cards will see 3.75GB of the 4GB installed. Others if they have really large graphics memory may only see 2GB of the 4GB. It is not a rip off - just the way that 32bit memory addressing works - if you want more then you have to move up to a 64bit OS.

Strange definition of a rip-off. Anyways, it's not really 3GB. 32bit can address 4GB of memory, but that includes video ram and all the other memory on the processor etc.

In reply to a post by Anonymous:

Hi,

So decided to add more memory to my pc and have 4GB instead 2GB. However pc was showing 3GB after installation and an online search on it suggested it is because it is 32 bit xp.

My question is, is there any point in having 4GB instead install when only 3GB is recognised? In that case is it better to just have 3GB in total installed?

The 4GB limit for 32bit operating systems (OS) which applies to any OS is arrived at by a mathematical formula, which looks complex but is not really.

For 32-bit systems:
232 = 4,294,967,296 bytes
4,294,967,296 / (1,024 x 1,024) = 4,096 MB = 4GB
Which is the theoretical limit for a 32 bit system, but this does not mean just the RAM you put in the slots. You have to take into account graphics memory etc.
If you install 4GB of RAM you are only likely to have 3 to 3.5GB actually available.

For 64-bit system:

264 = 18,446,744,073,709,551,616
18,446,744,073,709,551,616 / (1,024 x 1,024) = 16EB (exabytes)
One Exabyte (EB) is one billion Gigabyte (GB)

In practical terms, a 64bit operating system can use all the RAM you can put in the motherboard.
There are no motherboards available to the public that could take that amount of RAM but I seem to recall that Exabyte systems do exist but I can�t remember for definite!! The down side of being eligible for a bus pass.

Not all 32-bit Operating Systems are limited to 4GB of physical RAM. Think PAE.