RAM showing as 4.00Gb in system information (Vista) but only 2300 in task manager

dotdotme 2009-01-05 08:15:17 UTC #1

Hi all,

Happy New Year

In my PC i have 4GB of ram installed in the systmen nifo it shows as 4.00GB but i know this is just a tweak that microsoft has implied in their new servce pack to allow it to detect it but NOT use all of it!!!

Once i check in task manager it shows as only 2300 being addressed, it should atleast be 3500.

In my other PC it has 3.00GB of ram and it shows as 3GB in the task manager so why not on this one.

Thanks for your time and insight.

Bob 2009-01-05 08:22:15 UTC #2

You might need to turn on Remapping in your BIOS? I’m running 4 gigs of RAM with my Vi$ta 64 bit and had to turn on remapping in BIOS. (Asus P5B Deluxe WiFi)

dotdotme 2009-01-05 08:26:21 UTC #3

[QUOTE=Bob;2190047]You might need to turn on Remapping in your BIOS? I’m running 4 gigs of RAM with my Vi$ta 64 bit and had to turn on remapping in BIOS. (Asus P5B Deluxe WiFi)[/QUOTE]

can you tell me how becuase i have never seen that option in my bios, i have a dell xps 730.

Thanks

Bob 2009-01-05 08:28:10 UTC #4

[QUOTE=dotdotme;2190054]can you tell me how becuase i have never seen that option in my bios, i have a dell xps 730.

Thanks[/QUOTE]I’m not familiar with your mobo sorry. Maybe someone else will know.

qwakrz 2009-01-05 10:08:41 UTC #5

The main problem is you are running a 32bit O/S, this will limit the amount of memory you will see at the end.

XP / Vista 32bit can only address 4GB of memory area, from this area you have to remove any graphics card memory, sound card address memory (it takes some memory addresses so that the CPU can talk to it) any needed for network cards, I/O ports etc. This can mean that from 4GB of ram you are left with 2-3GB of free address space that can then be used by the memory modules as physical RAM.

To see all your 4GB of ram you will need to upgrade to a 64bit O/S and the only real one currently available is Vista 64bit (or Linux 64bit if you swing that way).

dotdotme 2009-01-05 10:40:03 UTC #6

[QUOTE=qwakrz;2190145]The main problem is you are running a 32bit O/S, this will limit the amount of memory you will see at the end.

To see all your 4GB of ram you will need to upgrade to a 64bit O/S and the only real one currently available is Vista 64bit (or Linux 64bit if you swing that way).[/QUOTE]

ok. but what if the graphics cards have their own memory becuase 512mb per GPU is fine so it shouldnt need my RAM. Also if the sound card ets are not on board woudnt that mean they can run without the RAM.

if not that atleast it should show more than 2.30GB in task manager ebcuase my other computer shows the full amount of 3gb in its task manager.

Thanks

qwakrz 2009-01-05 10:49:55 UTC #7

The card does have its own RAM but the CPU has to talk to this RAM so it has to take up space from that 4GB of address space. If you only had 2GB of RAM then the graphics memory would be mapped into non RAM space (but still below the 4GB limit) but as you have the max RAM then there is some overlap, in your case its the worst overlap where all the graphics RAM has to be mapped over the top of system RAM.

Also remember, the Graphics RAM is only part of the address space needed by the graphics card, the GPU also needs some address space as well so it can be programed, it all adds up.

The amount of RAM mapped over does depend on the BIOS as well. Using the same components but a different MOBO I could see 2.9GB compaired to 3.2GB of ram on my old Vista 32 install using the older mobo.

Either way, to see all your RAM is going to involve going for a 64bit O/S no matter what you do.

qwakrz 2009-01-05 10:57:40 UTC #8

For some further reading take a look at

http://channel9.msdn.com/forums/TechOff/41288-4GB-RAM/?CommentID=41350

There are a few posts that explain it a lot better than I have

There is also some comment on address space at http://blogs.msdn.com/oldnewthing/archive/2006/08/14/699521.aspx

I managed to get these links from http://www.hardforum.com/showthread.php?t=1035670 but some of the points in the posts are very muddy as the /PAE switch is only used on server operating systems (I.E Windows 2000 / 2003 / 2008 etc)

Bob 2009-01-05 11:34:28 UTC #9

I didn’t realize you were using 32 bit OS sorry.