Memory - 4gb vs 3gb vs 3.5gb

[bestbapu]

I have two mobo's that support 4gb of memory. mobo1 supports 4 slots of dual
channel (up to 4 gb) and mobo2 supports 2 slots of single channel memory (up
to 4gb).

Mobo1 when booted in XP32 shows 3.5gb of RAM (in System Properties).

Mobo2 when booted in XP32 shows 2.93gb of RAM (in System Properties).

Is this normal?

FYI: Mobo's are not by same manufacturer. Mobo1 is Gigabyte 8IPE1000 and
Mobo2 is MachSpeed P4MST-890.

Tia for any help,
Ed.

 

[Shenan Stanley]

I have two mobo's that support 4gb of memory. mobo1 supports 4
slots of dual channel (up to 4 gb) and mobo2 supports 2 slots of
single channel memory (up to 4gb).

Mobo1 when booted in XP32 shows 3.5gb of RAM (in System Properties).

Mobo2 when booted in XP32 shows 2.93gb of RAM (in System
Properties).

Is this normal?

FYI: Mobo's are not by same manufacturer. Mobo1 is Gigabyte
8IPE1000 and Mobo2 is MachSpeed P4MST-890.

It is normal.
If you want to actually utilize the 4GB - get a 64-bit OS.

 

[Ken Blake, MVP]

I have two mobo's that support 4gb of memory. mobo1 supports 4 slots of dual
channel (up to 4 gb) and mobo2 supports 2 slots of single channel memory (up
to 4gb).

Mobo1 when booted in XP32 shows 3.5gb of RAM (in System Properties).

Mobo2 when booted in XP32 shows 2.93gb of RAM (in System Properties).

Is this normal?

Yes.

All 32-bit versions of Windows (Vista as well as XP), even though they
have a 4GB address space, can only use *around* 3.1GB of RAM. That's
because some of that space is used by hardware and not
available to the operating system and applications. The amount you can
use varies, depending on what hardware you have installed, but is
usually around 3.1GB.

 

[John Barnett MVP]

If you want to use 4GB of memory or more you need the 64 Bit version of XP,
along with a PC that supports 64 Bit. If you put 4GB of memory into a 32 bit
machine it will show 4GB in the BIOS but Windows will only show it as a
maximum of 3GB.

--
--
John Barnett MVP
Associate Expert
Windows - Shell/User

Web: http://xphelpandsupport.mvps.org
Web: http://vistasupport.mvps.org

The information in this mail/post is supplied "as is". No warranty of any
kind, either expressed or implied, is made in relation to the accuracy,
reliability or content of this mail/post. The Author shall not be liable for
any direct, indirect, incidental or consequential damages arising out of the
use of, or inability to use, information or opinions expressed in this
mail/post..

 

[Jim]

I have two mobo's that support 4gb of memory. mobo1 supports 4 slots of
dual
channel (up to 4 gb) and mobo2 supports 2 slots of single channel memory
(up
to 4gb).

Mobo1 when booted in XP32 shows 3.5gb of RAM (in System Properties).

Mobo2 when booted in XP32 shows 2.93gb of RAM (in System Properties).

Is this normal?

FYI: Mobo's are not by same manufacturer. Mobo1 is Gigabyte 8IPE1000 and
Mobo2 is MachSpeed P4MST-890.

Tia for any help,
Ed.

Yes, this is normal.. Windows uses memory mapped I/O. This causes certain
parts of the 4GB address space to be reserved for use by I/O controllers.
As an O/S cannot allow two devices to respond to the same memory address,
Windows disables that part of the RAM which overlaps the I/O controllers.
There is a way to view the memory usage in msinfo32.
Jim

 

[Plato]

I have two mobo's that support 4gb of memory. mobo1 supports 4 slots of dual
channel (up to 4 gb) and mobo2 supports 2 slots of single channel memory (up
to 4gb).

Mobo1 when booted in XP32 shows 3.5gb of RAM (in System Properties).

Mobo2 when booted in XP32 shows 2.93gb of RAM (in System Properties).

Is this normal?

Yes.

 

[Tim Slattery]

I have two mobo's that support 4gb of memory. mobo1 supports 4 slots of dual
channel (up to 4 gb) and mobo2 supports 2 slots of single channel memory (up
to 4gb).

Mobo1 when booted in XP32 shows 3.5gb of RAM (in System Properties).

Mobo2 when booted in XP32 shows 2.93gb of RAM (in System Properties).

Is this normal?

Yes, although 2.93 is on the low end of what you'd expect to see
(IMHO). The 4GB address space must be used to address video memory,
BIOS, and other things. What ever is left over is used to access your
RAM. See http://members.cox.net/slatteryt/RAM.html