32 bit and 64 bit RAM access

  • Thread starter Thread starter Alan T
  • Start date Start date
A

Alan T

If I am using 32 bit Vista Ultimate, is that means 4 GB RAM is not better
than 2 GB?
Is 4 GB RAM only perform better in 64 bit than 32 bit Vista?
 
Hi Alan,

A 32-bit version of Vista can only access a maximum of 3.7GB of physical
memory that it can access (the rest of the 4GB address space is taken up by
the minimum page file allocation, which should be left as 'System Managed').
For practical purposes, I would recommend a maximum physical RAM size of 2GB
for 32-bit versions. The 64-bit versions do not have this limitation, so if
you have this version you can access much more memory and can fill your
motherboard up to its total memory capacity.
Dwarf
 
Dwarf,

I'm curious why you wouldn't recommend 3Gb of RAM rather than only 2GB for
32 bit systems.
Is there a particular reason?

Cheers
 
In message <[email protected]>
Rutetuti said:
I'm curious why you wouldn't recommend 3Gb of RAM rather than only 2GB for
32 bit systems.
Is there a particular reason?
Click to expand...

2GB keeps you in dual-channel mode (although technically 2x1GB+2x512MB
sticks would get you in dual-channel mode on some chipsets)

Most users don't even need 2GB though, so upgrading beyond that is
usually less useful, especially if you're upgrading because your
existing RAM is all in use (Vista tries it's best to use all RAM, so
having most/all of your RAM in use isn't always a bad thing)
 
Hi Rutetuti,

The reason that I recommend 2GB rather than 3GB in 32-bit systems is to do
with bandwidth. The bandwidth of a single stick of DDR PC3200 is 3200 Mb/sec
(single channel mode). In a dual channel configuration, this doubles to 6400
Mb/sec. This makes for a much more responsive system. This only works if the
memory is balanced - any inbalance (different module capacity, number of
slots occupied per channel) will cause the system to work in single channel
mode. Of course, if your system doesn't support dual channel memory you can
use 3GB of RAM.
Dwarf
 
If I am using 32 bit Vista Ultimate, is that means 4 GB RAM is not better
than 2 GB?
Click to expand...


No, it doesn't necessarily mean that. Two points.

1. All 32-bit versions of Windows, 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. But I've
seen numbers as high as 3.7GB.

2. That means that 3.1 *may* be an improvement over 2GB. If 3.1GB is
better than 2GB, then 4GB is also better than 2GB (but not better than
3.1GB, or however much of the 4GB your computer can use).

Note that I say "*may* be an improvement." Despite what many people
think, more RAM is *not* always better. It's true only up to a point.
You get good performance if the amount of RAM you have keeps you from
using the page file, and that depends on what apps you run. Once you
stop using the page file, adding more RAM does almost nothing for you.
That's true, not only in Vista, but in all versions of Windows.

Most people running Windows Vista, unless they perform particularly
memory-hungry tasks like video or large photo-editing, will see little
or no improvement past 2GB.

Is 4 GB RAM only perform better in 64 bit than 32 bit Vista?
Click to expand...


64-bit Windows will let you use the full 4GB--and more. Whether that
translates into better performance, again depends on what apps you
run. For most people, as I said above, that much RAM is overkill, and
simply a waste of money.
 
Dwarf said:
Hi Rutetuti,

The reason that I recommend 2GB rather than 3GB in 32-bit systems is to do
with bandwidth. The bandwidth of a single stick of DDR PC3200 is 3200 Mb/sec
(single channel mode). In a dual channel configuration, this doubles to 6400
Mb/sec. This makes for a much more responsive system. This only works if the
memory is balanced - any inbalance (different module capacity, number of
slots occupied per channel) will cause the system to work in single channel
mode. Of course, if your system doesn't support dual channel memory you can
use 3GB of RAM.
Dwarf
Click to expand...

But of course, if you install 4GB, and Windows only sees 3.5GB, you have
1.5GB more than if you only installed 2GB, and you still have dual channel
 
Hi Alan,

A 32-bit version of Vista can only access a maximum of 3.7GB of physical
memory that it can access (the rest of the 4GB address space is taken up by
the minimum page file allocation, which should be left as 'System Managed').
For practical purposes, I would recommend a maximum physical RAM size of 2GB
for 32-bit versions. The 64-bit versions do not have this limitation, so if
you have this version you can access much more memory and can fill your
motherboard up to its total memory capacity.
Dwarf





- Show quoted text -
Click to expand...

Go with that!
 
Ken Blake said:
No, it doesn't necessarily mean that. Two points.

1. All 32-bit versions of Windows, 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. But I've
seen numbers as high as 3.7GB.
Click to expand...

I get 3582MB of RAM with my 4GB 32-bit system. I have a 320MB graphics card
 
Back
Top