About memory sharing

Hi all, this is my first post here


I have a question that no one could answer me, and I can't stop thinking about it..
Well, the thing is, I have a laptop with 3GB DDR2 Ram and a 32bit Windows Vista installed on it, and, knowing that a 32bit OS can't handle more than 3GB, it occured to me that it would be nice if I could add 1GB to it (thus having 4gb) and using that 1GB that my system can't handle on my integrated graphics card. Would it be possible? Because even if Vista32 doesn't recognize the 1GB that I added, my BIOS will, and then I can use that to my advantage sharing only this 1GB, not 'stealing' from my actual memory.. So, is it possible? Thanks in advance

 

No, because to do that, assuming there is some way, windows has to recognize the memory to allow it for sharing. Therefore 3.8Gb is the maximum a 32-bit system can recognize.

 

There's 4 GB of addressing space on a 32-bit system. You can divide that 4 GB however you want, but there's no going over that limit.

 

Hmm 3.8? Then just buying 512mb and sharing it on the graphics card would be just as good for me Thank you very much

 

You can't have 3.5 GB in a system. They don't make 1.5 GB sticks of RAM. Futhermore, adding 512 MB of shared memory to your graphics card is not going to improve performance at all.

 

There's a total of 4Gb addressing space on a 32bit OS as Lithus mentioned. That limit includes the memory addressing of the GPU(actually, RAM usually comes near last in the order when the system addresses memory IIRC) so it's not really worth it to add more RAM.

From a GPU point of view, adding in more shared memory isn't going to do much anyways. I could add 1Gb of VRAM to a crappy HD4500 and it'd still be a crappy GPU. I'm going to assume the max shared memory it can take is say 512mb. Well it'll take those 512mb if it needs to(doubtful) regardless of your system RAM. The only performance difference is that you'll have less system RAM to work with during those periods of time. The GPU's performance won't be affected by more RAM really.

 

As far as I recall the total memory do not reach 4Gb exactly but less, 3.8Gb as I recall, but not 4Gb.

 

I was talking about total memory, not RAM specifically.

I'm no expert, but if I remember correctly, 4Gb is the total memory address(not RAM) limit of a 32bit OS. Memory address includes everything, not just RAM. This includes CPU memory, video memory and the like. RAM is actually one of the last thinsg to be addressed, hence why if you stick 4Gb, it's not fully recognized and addressed properly.

 

Yep even devices like network adapters and sound cards can take address space.

 

You want heard my solution...?

Just upgrade your OS into 64-bit and your problem about RAM is finish...

 

To clarify the above posts, Forever_Melody is pretty much right on, it's 4GB exactly, NOT 3.8 GB.
And RAM isn't almost last, it's dead last (otherwise, some hardware would not function when you exceeded your address space because of too much memory)

 

I thought the limit without PAE was 2^32 bytes (4,294,967,296 bytes)...which is 4 GiB.

 

GB and GiB is pretty much interchangeable (actually, no one here in the States would ever use GiB in normal conversation). Only on Wikipedia do people make a big fuss over it.