RAM help!

[Guest]

I am having a problem with the memory not being recongnized. I have 4gb
installed in my system, but when I go to view how much memory windows "sees,"
it only shows 3gb. I have 2 video cards that would take 256 each (a total of
512) so I believe that memory would go there, but what happened to the rest?
Also, when I turn on (or restart) the computer, the memory check shows 4096
so I know that the bios does "see" all 4gb.
Any suggestions? Thanks in advanced!

 

[John]

I am having a problem with the memory not being recongnized. I have 4gb
installed in my system, but when I go to view how much memory windows "sees,"
it only shows 3gb. I have 2 video cards that would take 256 each (a total of
512) so I believe that memory would go there, but what happened to the rest?
Also, when I turn on (or restart) the computer, the memory check shows 4096
so I know that the bios does "see" all 4gb.
Any suggestions? Thanks in advanced!

You might be better asking this question in a hardware newsgroup.

John.

 

[Bistey Csaba]

Its a addressing limitation 32 bit systems cant use the whole 4gb.

See link for details.

http://www.codinghorror.com/blog/archives/000811.html

Csaba

 

[M.I.5¾]

I am having a problem with the memory not being recongnized. I have 4gb
installed in my system, but when I go to view how much memory windows
"sees,"
it only shows 3gb. I have 2 video cards that would take 256 each (a total
of
512) so I believe that memory would go there, but what happened to the
rest?
Also, when I turn on (or restart) the computer, the memory check shows
4096
so I know that the bios does "see" all 4gb.
Any suggestions? Thanks in advanced!

You are running a 32 bit version of Windows.

All the hardware devices in your system require resources to run. Among
those resources required is an adressing range. That addressing range has
to come out of the 4Gb memory range that Windows will address. Thus if you
fit 4Gb of memory, not all of it will be available as the upper end of it
will be lost to the other devices.

64 bit Windows may well suffer a similar limitation but as the memory
addressing range is far larger, noone has hit it yet.

What are you doing that requires 4Gb of installed memory? It provides
little advantage for most applications. Even editing High definition video
can be accomplished in 1Gb of memory (though works a little faster with
2Gb).

 

[Ace]

I will argue with you that per 1Ghz you need/want 1GB RAM.
I say this from experience, have tested on 7 yearsv worth of hardware
generations, ranging from Pentium III 1Ghz upward to today. System will
perform much better when it has enough memory to process in, when the
opportunity to stay in RAM is there, OS will not reach for disk I/O,
fastest option has priority. This I have seen on Windows/*BSD/Linux
within various applications, such as desktop, multimedia, server uses.

On *BSD/Linux in particular it is easily visible when you have 'enough'
RAM, OS will not even touch swap. Other good example would be a
Microsoft Terminal Server. You need plenty of RAM for each desktop
session, when enough, disk I/O is reduced.

Has nothing to do with large files or improving program performance, it
is the disk I/O, this is and will for a long time be a bottleneck; adding
RAM minimizes disk I/O impact, it is just one benefit.
One could argue that for example, a laptop will not benefit from 2GB RAM
or more.
But I must be getting my 'quiet'4 hours battery time from somewhere.

 

[Tim Slattery]

I am having a problem with the memory not being recongnized. I have 4gb
installed in my system, but when I go to view how much memory windows "sees,"
it only shows 3gb. I have 2 video cards that would take 256 each (a total of
512) so I believe that memory would go there, but what happened to the rest?

It's used to map the BIOS, and whatever other PCI or PCIx components
you might have. See http://members.cox.net/slatteryt/RAM.html

 

[Bob I]

Sorry but that is complete bollocks! CPU frequency has zip point diddly
squat to do with RAM requirements. If anything one could argue that the
need is inverse.

 

[Ken Blake, MVP]

I am having a problem with the memory not being recongnized. I have 4gb
installed in my system, but when I go to view how much memory windows "sees,"
it only shows 3gb. I have 2 video cards that would take 256 each (a total of
512) so I believe that memory would go there, but what happened to the rest?
Also, when I turn on (or restart) the computer, the memory check shows 4096
so I know that the bios does "see" all 4gb.

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 3.5GB.

 

[Ace]

I could explain in more detail, but post would be too long.
Motherboard reserves RAM for BIOS/Video caching, command queue, Hardware
IRQ sharing, Memory mapping, etc.
CPU on motherboard is assigned similar resources, shares I/O with
motherboard main data bus, DMA channels, RAM, other peripherals on bus.
You can run a 3.0Ghz processor just fine on 256MB RAM. But will it
perform the tasks it is presented with just as fast as advertised on it's
box when it has to wait for disk I/O requests to complete?
CPU <-> Board <-> Data Bus <-> Disk
OS will start to swap to disk when RAM is not sufficient, this is normal,
default behaviour.
Sadly, disk I/O still makes us, and our CPUs wait.
Perhaps now you understand what I mean when I say that 1GB RAM per 1Ghz
of processor speed means that this RAM is used to process information
faster than disk; your OS caches the data that is needed for processing
in RAM, CPU will access RAM directly and process there, rather than on
disk.
More RAM, better processing.


Theory vs. Practise

 

[Bob I]

Sadly, your theory that 1 Ghz of CPU frequency has any thing to do with
the number of GB of RAM is so far fetched as to be incredible! The RAM
requirement has everything to do with the application count and mix the
computer is used for.

 

[Ace]

You missed the point, but that is okay.
I suppose I am not that good at explaining it.

 

[John John]

More RAM will only improve performance if there is disk paging.
Otherwise, it will make no difference in the performance of the machine.
As Bob said, the notion the the amount of RAM should be matched to the
processor speed is far fetched!

John

 

[Unknown]

What you just said is also far fetched. More RAM diminishes the requirement
for paging. More RAM will improve performance regardless of paging.

 

[John John]

More RAM will only make a difference in performance *if* the computer is
paging. If the computer isn't paging adding more RAM will not make a
hill of beans of difference! More RAM will *NOT* increase performance
"regardless of paging", if the computer isn't paging it has sufficient
RAM or more than it needs for the applications that it is running. And
yes, it is far fetched to claim that the amount of RAM should be gauged
to the processor speed.

John

 

[Gotde T Shirt]

AIUI Windows uses spare RAM for caching disk data, so more RAM = more
caching = improved system performance.

 

[John John]

If you aren't using the pagefile it doesn't matter. Caching data that
you won't reuse makes no difference to performance. How much RAM you
need and whether or not adding more RAM will increase performance
depends on what you do with your computer. If all you do is play
Solitaire, do light internet browsing and send emails to grandma you
wont gain anything by doubling your RAM from 512MB to 1GB, you will just
be wasting your money on RAM that you don't need. To determine whether
or not adding RAM will improve performance you can monitor your system
for memory bottlenecks then make decisions based on actual RAM usage.

John

 

[jorgen]

If you aren't using the pagefile it doesn't matter. Caching data that
you won't reuse makes no difference to performance. How much RAM you
need and whether or not adding more RAM will increase performance
depends on what you do with your computer.

If there is plenty of unused memory, the OS has the opportunity to try
and guess what the user wants to do in the near future, and preload
programs into memory, so they're are ready to go when needed.

So I guess we make Microsoft happy, if we install more memory than we
really need

 

[John John]

If there is plenty of unused memory, the OS has the opportunity to try
and guess what the user wants to do in the near future, and preload
programs into memory, so they're are ready to go when needed.

And if you don't need them, what purpose does it serve? If more is
better should we all stick 3 or 4 Gigs in our machines? Is that enough
or should we all move to a 64-bit platform and stick even more in our
computers? If all you do is write memos and one page Word documents
will you notice an increase in performance if you add an extra gig of
RAM to the 1 Gig you already have? Adding more RAM to a computer that
already has sufficiently adequate RAM for the tasks and programs being
run is a waste of money.

So I guess we make Microsoft happy, if we install more memory than we
really need

Why would that make Microsoft happy? Microsoft doesn't sell RAM.

John

 

[jorgen]

And if you don't need them, what purpose does it serve? If more is
better should we all stick 3 or 4 Gigs in our machines? Is that enough
or should we all move to a 64-bit platform and stick even more in our
computers? If all you do is write memos and one page Word documents
will you notice an increase in performance if you add an extra gig of
RAM to the 1 Gig you already have? Adding more RAM to a computer that
already has sufficiently adequate RAM for the tasks and programs being
run is a waste of money.

It was just to throw something more into the thread. Your statement was
that unless the pagefile is taken into use, more ram will be absolutely
useless. I'm just saying, techniques like vista's superfetch makes that
statement less true

 

[John John]

It was just to throw something more into the thread. Your statement was
that unless the pagefile is taken into use, more ram will be absolutely
useless. I'm just saying, techniques like vista's superfetch makes that
statement less true

This is an XP group so what does Vista have to do with things here? The
only thing that prefetch or Vista's superfetch can do is save 1 or 2
seconds when loading an application, for people who only run a few
applications it still doesn't make a hill of beans.

John