4 gb Ram help

H

Hardware_freak

Disciple
Jun 8, 2006
148
2
0
36
Hi,
I am currently having 2gb of ram & i want to know wht will happen if in install more 2gb i.e total of 4gb ram.

1.will my 32 bit vista detect it.
2.if it detect around 3gb then does that mean the rest of ram is waste.
3.is there any way i can make it recognize my 4gb ram.
 
M

MAGNeT

Skilled
May 4, 2005
3,771
145
152
on vista 32 bit i dont guess u can detect 4gb......

its all about addressing.....

3gb only reaches the limit of 32bit....
 
C

Chaos

Skilled
Jan 29, 2005
9,603
1,572
302
32bit Windows will detect 4GB assuming u have the memory hole/MMIO or a similar option enabled in the bios. However a single app can max access 3GB. You'd have to specify the /3GB switch in the bootloader.
 
S

SharekhaN

Skilled
Aug 2, 2006
1,794
85
138
40
Yea providing if you dont have a GFX card or a sound card seperately . or else you will see only 3 Gb of addressable ram .
 
S

SharekhaN

Skilled
Aug 2, 2006
1,794
85
138
40
^^ that is correct .
The processor only has 32 address lines, limiting it to an addressing map of 4 gigabytes.

The chipset, PCI devices, PCI express region, and video cards use some of this map, and the BIOS correctly reports this range as unavailable to the operating system. If the user installs 4 GB of physical memory, then the processor has no way to address the memory that overlaps with these regions, already in use. The chipset directs memory access to the appropriate device rather than sending it to random access memory (RAM).

PCI express uses 500 megabytes (MB) in the map; integrated video takes 256 MB right below PCI express, leaving 3.25 GB of memory available to the operating system via RAM. In some cases, less RAM is available depending on what other add-in cards are installed.

For more info :
Comparison of 32-bit and 64-bit memory architecture for 64-bit editions of Windows XP and Windows Server 2003
 
  • Like
Reactions: 3 people
D

Deepak

Skilled
Oct 10, 2005
2,023
64
137
39
^^ Studied Microprocessor Architecture have you :p

and what he said is pretty much true, this limitation is removed in x64 with upto 64TB of memory mapping possible IIRC (will have to check, its a large no, I think 40 bits are available, not sure)
 
H

Hardware_freak

Disciple
Jun 8, 2006
148
2
0
36
Well but i am having a 64bit processor, so it has more address lines.

btw

1.can i install vista 32bit & 64bit together.

2.can i run 32bit application on vista 64 bit.

3.is vista 64bit faster than 32bit.
 
D

Deepak

Skilled
Oct 10, 2005
2,023
64
137
39
H

Hardware_freak

Disciple
Jun 8, 2006
148
2
0
36
Well Thanks guys for helping me

I think i will first buy more ram & then if it detects then it's good otherwise i will install both 32 & 64 bit os.
 
D

Deepak

Skilled
Oct 10, 2005
2,023
64
137
39
abhishek, thats a board problem, read below too, many people are working with more then 4gigs of RAM there
 
Top Bottom