MEMORY SIZES YOU CAN USE IN WINDOWS - ANSWER TO ALL WHO WONDER

  • Thread starter Thread starter JewBoy
  • Start date Start date
J

JewBoy

You wouldn't waste money if you install 4GB REGARDLESS of Windows (starting
w/Vista) or hardware (starting w/post-2006) you have, but you can do more,
read my article:
*****

As you know from Electrical Engineering basics, theoretical memory space is
defined by the address bus width. In a binary system it's simply 2^N where
N is the address width.
In plain English:
If your Windows is 32-bit it can theoretically manage 2^32 = 4GB.
If your hardware (e.g. Intel945 chipset?) is 32 bit but Windows is 64 bit,
or hardware is 64bit but Windows is 32 bit it's still 4GB as obviously the
lower address width limits the system, and disregards 64 bit elsewhere.

The practical numbers are somewhat different:
a) Windows 32-bit claims a whopping 0.75GB for itself ("untouchable" by
you - the user) due to I/O overhead in a 4GB memory space leaving you with
ONLY 3.25GB of usable memory
Too long to explain but just accept it as a fact - almost a Gigabyte is
eaten by the BIOS, I/O, etc. memory addresses your applications cannot use.
cool.gif
On the upside you can go over 4GB EVEN in a 32-bit Windows if this
Windows is a Server, and not a Client version.
There's a 99.9% chance you running a Client and not Server Windows, so your
usable memory is therefore:
3.25GB But I don't know exactly what Win version you run, so you can
calculate by understanding this article, i.e if you're so advanced as to
have Windows SERVER edition, then even in 32-bit configuration it can "page"
more than 4GB.

Now why I say you didn't waste money.
How much did you pay for 4GB and how much WOULD you pay for 3GB? The
$dollar difference as of September2009 is NOT worth any regret.
You'd lose pennies, stop worrying & have at least 4GB. Also better if you
install memory modules "symmetrically" which, as a consequence, also means
you'd have an even number of memory units.
In plain English, it's better to install two modules 2GB+2GB = 4GB, than
2GB+1GB = 3GB which is assymetric, although such may not longer be of any
importance for new computers, in the past it was an issue. Still I
recommend not to play with assymetry for DDR2 memory, I don't know about
DDR3 and this example covers 4GB. You might have 4GB+4GB=8GB for example,
for 64-bit Windows AND 64-bit hardware as a requirement.
Why would anyone need 8GB? Well, I even need MORE - 16GB for
CAD/Engineering & Graphics design work, so I can lots of memory running
heavy-duty engineering simulations.
Plus it stimulates industry (but hurts environment) heheh....

So memory space is defined by 3 factors:
OS bit width
Hardware bitwidth
Whether your Windows addressing is using virtuial/paging/etc to bypass
normal addressing limted to 2^N - i.e. is it a regular Win Client or Server,
and how much your Windows wastes for itself (overhead)
I am not likely to check your further questions, so dont ask
smile.gif
I am too
busy, maybe others will help more.
Just get 4GB and be done with it.

BUT IF YOU NEED 1GB+1GB MODULES = 2GB of laptop, DDR667 speed memory, let me
know - I can ship for free (you just pay shipping by Post Office in USA or
abroad), I removed them and replaced with 8GB on my laptop. I am too lazy
to write ads and sell it, just take for free. I maybe back here to check
your response for thsi reason only.
 
"JewBoy" wrote in message
news:#yDffX0IKHA.4376@TK2MSFTNGP03.phx.gbl...
> You wouldn't waste money if you install 4GB REGARDLESS of Windows
> (starting w/Vista) or hardware (starting w/post-2006) you have, but you
> can do more, read my article:
> *****
>
> As you know from Electrical Engineering basics, theoretical memory space
> is
> defined by the address bus width. In a binary system it's simply 2^N
> where
> N is the address width.
> In plain English:
> If your Windows is 32-bit it can theoretically manage 2^32 = 4GB.
> If your hardware (e.g. Intel945 chipset?) is 32 bit but Windows is 64 bit,
> or hardware is 64bit but Windows is 32 bit it's still 4GB as obviously the
> lower address width limits the system, and disregards 64 bit elsewhere.
>
> The practical numbers are somewhat different:
> a) Windows 32-bit claims a whopping 0.75GB for itself ("untouchable" by
> you - the user) due to I/O overhead in a 4GB memory space leaving you with
> ONLY 3.25GB of usable memory
> Too long to explain but just accept it as a fact - almost a Gigabyte is
> eaten by the BIOS, I/O, etc. memory addresses your applications cannot
> use.
>
cool.gif
On the upside you can go over 4GB EVEN in a 32-bit Windows if this
> Windows is a Server, and not a Client version.
> There's a 99.9% chance you running a Client and not Server Windows, so
> your
> usable memory is therefore:
> 3.25GB But I don't know exactly what Win version you run, so you can
> calculate by understanding this article, i.e if you're so advanced as to
> have Windows SERVER edition, then even in 32-bit configuration it can
> "page"
> more than 4GB.
>
> Now why I say you didn't waste money.
> How much did you pay for 4GB and how much WOULD you pay for 3GB? The
> $dollar difference as of September2009 is NOT worth any regret.
> You'd lose pennies, stop worrying & have at least 4GB. Also better if you
> install memory modules "symmetrically" which, as a consequence, also means
> you'd have an even number of memory units.
> In plain English, it's better to install two modules 2GB+2GB = 4GB, than
> 2GB+1GB = 3GB which is assymetric, although such may not longer be of any
> importance for new computers, in the past it was an issue. Still I
> recommend not to play with assymetry for DDR2 memory, I don't know about
> DDR3 and this example covers 4GB. You might have 4GB+4GB=8GB for example,
> for 64-bit Windows AND 64-bit hardware as a requirement.
> Why would anyone need 8GB? Well, I even need MORE - 16GB for
> CAD/Engineering & Graphics design work, so I can lots of memory running
> heavy-duty engineering simulations.
> Plus it stimulates industry (but hurts environment) heheh....
>
> So memory space is defined by 3 factors:
> OS bit width
> Hardware bitwidth
> Whether your Windows addressing is using virtuial/paging/etc to bypass
> normal addressing limted to 2^N - i.e. is it a regular Win Client or
> Server,
> and how much your Windows wastes for itself (overhead)
> I am not likely to check your further questions, so dont ask
smile.gif
I am too
> busy, maybe others will help more.
> Just get 4GB and be done with it.
>
> BUT IF YOU NEED 1GB+1GB MODULES = 2GB of laptop, DDR667 speed memory, let
> me
> know - I can ship for free (you just pay shipping by Post Office in USA or
> abroad), I removed them and replaced with 8GB on my laptop. I am too lazy
> to write ads and sell it, just take for free. I maybe back here to check
> your response for thsi reason only.
>


32-bit doesn't theoretically manage 4gb. It does manage it. But 'it' has to
include the motherboard in the total 4gb..

--

Mike Hall - MVP Windows Experience
http://msmvps.com/blogs/mikehall/
 
Quit reading so much Russinovich.

Saucy


"Mike Hall - MVP" wrote in message
news:ugKcc61IKHA.4168@TK2MSFTNGP05.phx.gbl...
>
>
> 32-bit doesn't theoretically manage 4gb. It does manage it. But 'it' has
> to include the motherboard in the total 4gb..
>
> --
>
> Mike Hall - MVP Windows Experience
> http://msmvps.com/blogs/mikehall/
 
On Sat, 22 Aug 2009 12:49:28 -0500, JewBoy wrote:

> You wouldn't waste money if you install 4GB REGARDLESS of Windows
> (starting w/Vista) or hardware (starting w/post-2006) you have, but you
> can do more, read my article:
> *****
>
> As you know from Electrical Engineering basics, theoretical memory space
> is defined by the address bus width. In a binary system it's simply 2^N
> where N is the address width.
> In plain English:
> If your Windows is 32-bit it can theoretically manage 2^32 = 4GB. If
> your hardware (e.g. Intel945 chipset?) is 32 bit but Windows is 64 bit,
> or hardware is 64bit but Windows is 32 bit it's still 4GB as obviously
> the lower address width limits the system, and disregards 64 bit
> elsewhere.


Interesting trick - I didn't know you could run the 64bit version on
32bit hardware.


>
> The practical numbers are somewhat different: a) Windows 32-bit claims a
> whopping 0.75GB for itself ("untouchable" by you - the user) due to I/O
> overhead in a 4GB memory space leaving you with ONLY 3.25GB of usable
> memory
> Too long to explain but just accept it as a fact - almost a Gigabyte is
> eaten by the BIOS, I/O, etc. memory addresses your applications cannot
> use.
cool.gif
On the upside you can go over 4GB EVEN in a 32-bit Windows if
> this Windows is a Server, and not a Client version. There's a 99.9%
> chance you running a Client and not Server Windows, so your usable
> memory is therefore:
> 3.25GB But I don't know exactly what Win version you run, so you can
> calculate by understanding this article, i.e if you're so advanced as to
> have Windows SERVER edition, then even in 32-bit configuration it can
> "page" more than 4GB.
>
> Now why I say you didn't waste money. How much did you pay for 4GB and
> how much WOULD you pay for 3GB? The $dollar difference as of
> September2009 is NOT worth any regret. You'd lose pennies, stop worrying
> & have at least 4GB. Also better if you install memory modules
> "symmetrically" which, as a consequence, also means you'd have an even
> number of memory units. In plain English, it's better to install two
> modules 2GB+2GB = 4GB, than 2GB+1GB = 3GB which is assymetric, although
> such may not longer be of any importance for new computers, in the past
> it was an issue. Still I recommend not to play with assymetry for DDR2
> memory, I don't know about DDR3 and this example covers 4GB. You might
> have 4GB+4GB=8GB for example, for 64-bit Windows AND 64-bit hardware as
> a requirement. Why would anyone need 8GB? Well, I even need MORE - 16GB
> for CAD/Engineering & Graphics design work, so I can lots of memory
> running heavy-duty engineering simulations.
> Plus it stimulates industry (but hurts environment) heheh....
>
> So memory space is defined by 3 factors: OS bit width
> Hardware bitwidth
> Whether your Windows addressing is using virtuial/paging/etc to bypass
> normal addressing limted to 2^N - i.e. is it a regular Win Client or
> Server, and how much your Windows wastes for itself (overhead) I am not
> likely to check your further questions, so dont ask
smile.gif
I am too busy,
> maybe others will help more.
> Just get 4GB and be done with it.
>
> BUT IF YOU NEED 1GB+1GB MODULES = 2GB of laptop, DDR667 speed memory,
> let me know - I can ship for free (you just pay shipping by Post Office
> in USA or abroad), I removed them and replaced with 8GB on my laptop. I
> am too lazy to write ads and sell it, just take for free. I maybe back
> here to check your response for thsi reason only.
 
"JewBoy" wrote in message
news:e2NLZA4IKHA.5956@TK2MSFTNGP03.phx.gbl...
>> 32-bit doesn't theoretically manage 4gb. It does manage it. But 'it' has
>> to include the motherboard in the total 4gb..

>
> What is the point of repeating my post in a twisted way? How different
> was my saying from yours? I know how.
> Just to indicate you know more than me?
>
> You softie guys should mind your own area, anbd we hardware guys make your
> softie run practically instead of paper/pen.

It wasn't a twist on what you said. Windows doesn't THEORETICALLY manage
4gb. It ACTUALLY manages it.

And Windows doesn't claim a whopping 0.75gb for itself. When Windows runs,
it takes into account the address space of the motherboard and only
allocates installed RAM up to the 4gb limit, ignoring whatever may be left
over. Some motherboards have an address space less than 1gb, and some have
slightly more. The figures for all motherboard makes and models are not
documented.

Your other points about buying 2 x 2gb because it is generally more
economical and better for dual channel are good and valid.

--

Mike Hall - MVP Windows Experience
http://msmvps.com/blogs/mikehall/
 
Whatever... you get the idea - lowest component limit (hard or soft), limits
entire system regardless of higher limits elsewhere in system also I hate
when good old definitions are twsited form Science into Commercial arena.
32 bit shoul dalways mean 32-bit bus - address or data, depending on what
you're talking about, in the case of memory it's the address bus.

BUT Windows Server blatantly may call itself 32-bit when in fact it plugs
64-bit plumbing and can manage ovcer 4GB, confusing poor end users totally.
 
> 32-bit doesn't theoretically manage 4gb. It does manage it. But 'it' has
> to include the motherboard in the total 4gb..


What is the point of repeating my post in a twisted way? How different was
my saying from yours? I know how.
Just to indicate you know more than me?

You softie guys should mind your own area, anbd we hardware guys make your
softie run practically instead of paper/pen.
 
OK but I didn't a heavy payload to this English word "theoretical". Maybe
it's slightly different meaning in Russian...

Back to design... alone in New Jersey office hehe..
 
Mike Hall - MVP wrote:
>
> "JewBoy" wrote in message
> news:e2NLZA4IKHA.5956@TK2MSFTNGP03.phx.gbl...
>>> 32-bit doesn't theoretically manage 4gb. It does manage it. But 'it'
>>> has to include the motherboard in the total 4gb..

>>
>> What is the point of repeating my post in a twisted way? How
>> different was my saying from yours? I know how.
>> Just to indicate you know more than me?
>>
>> You softie guys should mind your own area, anbd we hardware guys make
>> your softie run practically instead of paper/pen.
>
> It wasn't a twist on what you said. Windows doesn't THEORETICALLY manage
> 4gb. It ACTUALLY manages it.
>
> And Windows doesn't claim a whopping 0.75gb for itself. When Windows
> runs, it takes into account the address space of the motherboard and
> only allocates installed RAM up to the 4gb limit, ignoring whatever may
> be left over. Some motherboards have an address space less than 1gb, and
> some have slightly more. The figures for all motherboard makes and
> models are not documented.
>
> Your other points about buying 2 x 2gb because it is generally more
> economical and better for dual channel are good and valid.
>
Don't forget, if you have a graphics card with on-board ram, that also
eats into the memory map. My sisters PC has 4GB of physical ram
installed, but she also has a GPU card with a Gigabyte of on-board ram
and windows only shows 2.5GB of memory.
 
"Anon" wrote in message
news:OSokCADJKHA.1340@TK2MSFTNGP05.phx.gbl...
> Mike Hall - MVP wrote:
>>
>> "JewBoy" wrote in message
>> news:e2NLZA4IKHA.5956@TK2MSFTNGP03.phx.gbl...
>>>> 32-bit doesn't theoretically manage 4gb. It does manage it. But 'it'
>>>> has to include the motherboard in the total 4gb..
>>>
>>> What is the point of repeating my post in a twisted way? How different
>>> was my saying from yours? I know how.
>>> Just to indicate you know more than me?
>>>
>>> You softie guys should mind your own area, anbd we hardware guys make
>>> your softie run practically instead of paper/pen.

>>
>> It wasn't a twist on what you said. Windows doesn't THEORETICALLY manage
>> 4gb. It ACTUALLY manages it.
>>
>> And Windows doesn't claim a whopping 0.75gb for itself. When Windows
>> runs, it takes into account the address space of the motherboard and only
>> allocates installed RAM up to the 4gb limit, ignoring whatever may be
>> left over. Some motherboards have an address space less than 1gb, and
>> some have slightly more. The figures for all motherboard makes and models
>> are not documented.
>>
>> Your other points about buying 2 x 2gb because it is generally more
>> economical and better for dual channel are good and valid.
>>
> Don't forget, if you have a graphics card with on-board ram, that also
> eats into the memory map. My sisters PC has 4GB of physical ram
> installed, but she also has a GPU card with a Gigabyte of on-board ram and
> windows only shows 2.5GB of memory.

When I ran 32-bit, I had a 256mb video card and lost 0.75gb overall. It
could be that most motherboards take up 0.5 plus whatever the onboard GPU
memory is. Would sound about right for my system and the one that you refer
to..

--

Mike Hall - MVP Windows Experience
http://msmvps.com/blogs/mikehall/
 
JewBoy wrote:

> Whether your Windows addressing is using virtuial/paging/etc to bypass
> normal addressing limted to 2^N


About that. It is done simply by using an extended page table layout
provided by the CPU. It is still the same process, there are just more
addressing bits in the PTE.
 
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