How much memory do I have?

[Kevin J. Cummings]

On 09/21/2009 06:06 PM, Hiisi wrote:
> Original Poster, sorry for intruding the thread, but I have small
> question to ask for those Gurus.
> How much memory can I have on my computer? It's 32 bit desktop:

It depends on a lot of things, but mostly your system motherboard.
Different boards allocate their memory differently.  Especially with
32-bit only CPUs.

> Linux imt.ru 2.6.30.5-43.fc11.i586 #1 SMP Thu Aug 27 21:18:54 EDT 2009
> i686 i686 i386 GNU/Linux
> Memory section of lshw says:
>      *-memory
>           description: System Memory
>           physical id: 19
>           slot: System board or motherboard
>           size: 512MiB
>           capacity: 2GiB
> 
> If I understand that correctly I'm not allowed to add more that 2GiB?

That's what the above seems to indicate for your motherboard.

> Using PAE kernel will I be able to install 4Gib?

No, if the motherboard isn't capable of handling more than 2GiB, then
that's your max.  My laptop has a max of 2GiB as well.  And its running
an Intel Core2 CPU which is 64-bits.  But, it can't use more than 2GiB
of RAM.

> Thanks for attention!

Each mother board has its own restrictions.  It should be in the User
Guide for either your system (if its a brand name system) or your mother
board.  I have found the site:  www.crucial.com  is a good repository
for amounts of MAX memory (they tell you what the max amounts are if you
can tell them the system/motherboard brand and model number.

I have had computers with max motherboard amounts of:  384MiB, 512MiB,
1GiB, 2GiB, 4GiB*, and I've seen systems with max amounts of 8GiB,
16GiB, and more.

I put a "*" next to the 4GiB amount because sometimes motherboard
designs limit the actual amount of available memory to 3GiB or 3.5GiB
due to memory mappings (esp with 32-bit CPUs), and most 32-bit OSes
can't use more than 4GiB max anyways.

Also, sometimes, the CMOS Setup has a setting controlling how much
memory is made available to the OS.

PAE (Physical Address Extensions) can be used with most modern
CPUs (when run in 32-bit mode), but since most modern CPUs are 64-bit
capable, why would you run a 32-bit OS on them?  Even Windows is now
shipping 64-bit Vista and Windows-7 on new processors.  The default
kernels for Fedora 11 are PAE capable, so if your motherboard can
see/use more than 3GiB, you should get use of the max amount of memory.
I've read a couple of good explanations online about the limits of
memory on 32-bit motherboards.  Google for them, they're pretty easy to
find.

-- 
Kevin J. Cummings
kjchome at rcn.com
cummings at kjchome.homeip.net
cummings at kjc386.framingham.ma.us
Registered Linux User #1232 (http://counter.li.org)