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Ram upgrade but BIOS detects less than advertised


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#1 Zoso

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Posted 15 December 2016 - 06:44 AM

someone gave me a core2 duo laptop that only had 512mb RAM installed but manufacturer indicates that it is upgradable to 4GB.

it is DDR2 and takes 2x2gb so I bought a kit off amazon. its Corsair brand or at least thats what the package indicates and it is a sealed package that appears authentic but after i installed it the bios only detects 3328mb upon boot up self test.

windows BGInfo and coolmon both show it on the desktop as 3328mb also however all the system spec tools ive run that just list various specs all say its 2x2gb 667mhz as advertised.

did a search on this particular laptop to see if it was a common issue and found nothing.

the laptop needed a bios upgrade too so I did that prior to installing the RAM.

is fake RAM an issue these days? I dont have any other compatible hardware that I can put it into to see if it gives the same result. any other way to test it? I'd like to verify that it is not the laptop causing the issue before I go about returning the RAM.

all the older version of the BIOS firmware are still available, maybe I should revert back to an older version just to see if that makes any difference?

what would you do in this situation? any tools available specifically for testing this kinda thing?

thanks

#2 Wonko the Sane

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Posted 15 December 2016 - 09:28 AM

Which make/model of laptop?

Which OS?

Don't tell me Windows XP SP2 or a later MS 32 bit OS, please ... :whistling:

What do you see in the BIOS? (amount of ram should be displayed there)

Check if you have in BIOS a "memory remapping" (or similar) option.

Of course you can test the single sticks one by one, testing with the one or the other inserted if you have 2 Gb of RAM.

 

:duff:

Wonko



#3 steve6375

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Posted 15 December 2016 - 12:59 PM

What you see is not uncommon. Many chipsets use high memory for memory-mapped registers and this wastes a lot of upper memory space.

 

With old chipsets and BIOSes, it was thought that no one would fit 4GB of memory because who would possibly need that much memory!

 

Go to Windows Devman - View - Resources by connection - Memory

 

See if anything is taking up memory at 3328MB+   = 0xd0000000 to 0xFFFFffff

 

Also, the BIOS should report a RAM Map which Windows can use (so there may be holes in the memory map of large amounts of usable RAM). If the BIOS does not report these correctly then Windows will not use them.

You can boot to grub4dos on a USB drive (e.g. a Easy2Boot USB stick), go to the grub4dos console and type displaymem to see the BIOS reported memory map - look for 'Usable RAM' areas

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#4 cdob

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Posted 15 December 2016 - 04:29 PM

a core2 duo laptop

3328mb ... 2x2gb 667mhz

A core2duo at 667mhz indicates a I945 chipset.
A I945 chipset supports max 4 GB address space, there are 32 Bit lines at the motherboard.
The graphic card is addressed at this 32 Bit lines too. The physical RAM at graphic card address space is not accessable.
The chipset dosn't remap the physical RAM to higher addresses, not all physical RAM is available.
It's a hardware limitation.

#5 Zoso

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Posted 15 December 2016 - 06:09 PM

Which make/model of laptop?
Which OS?
Don't tell me Windows XP SP2 or a later MS 32 bit OS, please ... :whistling:
What do you see in the BIOS? (amount of ram should be displayed there)
Check if you have in BIOS a "memory remapping" (or similar) option.
Of course you can test the single sticks one by one, testing with the one or the other inserted if you have 2 Gb of RAM.

:duff:
Wonko

hi Wonko, its a toshiba a8-ez8312 that came with XPx86. i see the 4096mb in BIOS and no remapping options there.

"test a single stick" why didnt i think of that?.. that will do it, that will work! thanks



What you see is not uncommon. Many chipsets use high memory for memory-mapped registers and this wastes a lot of upper memory space.

With old chipsets and BIOSes, it was thought that no one would fit 4GB of memory because who would possibly need that much memory!

Go to Windows DiskMgmt - View - Resources by connection - Memory

See if anything is taking up memory at 3328MB+ = 0xd0000000 to 0xFFFFffff

Also, the BIOS should report a RAM Map which Windows can use (so there may be holes in the memory map of large amounts of usable RAM). If the BIOS does not report these correctly then Windows will not use them.
You can boot to grub4dos on a USB drive (e.g. a Easy2Boot USB stick), go to the grub4dos console and type displaymem to see the BIOS reported memory map - look for 'Usable RAM' areas

hi steve6375, i dont know how to interpret this but here is a screenshot from devman:

computer-250736.jpg


A core2duo at 667mhz indicates a I945 chipset.
A I945 chipset supports max 4 GB address space, there are 32 Bit lines at the motherboard.
The graphic card is addressed at this 32 Bit lines too. The physical RAM at graphic card address space is not accessable.
The chipset dosn't remap the physical RAM to higher addresses, not all physical RAM is available.
It's a hardware limitation.

hi cdob, i noticed that last BIOS updates detail note mention something about:

When the system memory is 1GB or more in Vista, up to 256MB can be used as Video RAM. A Display Driver update is also required.

from: http://support.toshi...1364540&osId=48

so this is probably the case here.

is it possible that the older BIOS versions would change the memory allocations at all then?

thanks for the help and info guys!

#6 cdob

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Posted 15 December 2016 - 06:33 PM

http://support.toshi...1364540&osId=48

It's a 945GM chipset.
Accessing 4 GB physical RAM is impossible.
It's the hardware, the BIOS can not enable full RAM.

#7 Wonko the Sane

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Posted 15 December 2016 - 07:00 PM

As a side note, generically speaking, the issue may be two-fold.

One could be a limitation in BIOS.

Another one could be the OS itself (and/or PAE settings).

See also here:
http://reboot.pro/to...2bit-35gb-25gb/

Particularly:
http://reboot.pro/to...gb/#entry199544

http://www.unawave.d...er.html?lang=EN

 

In other words, even if the BIOS does see the "whole" 4 Gb, (or can remap it) the OS might not.

 

But if the chipset is 945 series, there is no way:
http://www.laptopmem...reports-3gb-why

 

BUT check it thoroughly:

https://readmystuff....o-have-4gb-ram/

 

See if the (older) freeware version of SIW:

http://www.afterdawn...fm#all_versions

or SIV:

http://rh-software.com/

identify the chipset.

 

:duff:
Wonko



#8 Zoso

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Posted 15 December 2016 - 08:49 PM

so it is most definitely a hardware limitation, cdob?

siw report:
computer-472359.jpg

this sys had several BIOS updates made available
computer-124039.jpg
computer-863591.jpg


if not hardware limit (how to determine/verify this?), i wonder if any of them would allow full usage of the 4GB? seems early versions were non compliant to intels instructions and maybe that limitation was one of them?


I will install w7 next and see what is indicates.

thanks

#9 cdob

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Posted 15 December 2016 - 09:36 PM

http://support.toshi...1364540&osId=48
Tecra A8-EZ8312 Detailed Specs (PDF)

5 Memory
For PC's configured with 4 GB of system memory, the full system memory space for computing activities will be considerably less


It's the hardware.

http://www.intel.com...-datasheet.html
9.2

The Memory Controller Hubs provides a maximum DRAM address decode space of 4 GB. The MCH does not remap APIC or PCI Express memory space. This means that as the amount of physical memory populated in the system reaches 4 GB, there will be physical memory that exists yet is non-addressable and therefore unusable by the system.



#10 steve6375

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Posted 15 December 2016 - 11:56 PM

Your Memory Map shows system resources from CF790000 upwards, so it cannot map RAM there.

This means that almost 1GB of your RAM is unusable.

It is a limitation of the chipset.

We used to get complaints from customers about this but there is nothing that can be done.



#11 Zoso

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Posted 16 December 2016 - 03:10 AM

is there anything grub4dos or imdisk can do with the unmapped portion? doesnt seem so if it is a hardware issue but since i dont know, i have to ask lol.

BTW, i installed W7x86 and it indicates "4GB RAM, 3.26 useable", i then used PaePatch to modify w7 to use more than 4GB RAM on it just to see what happens and it wouldnt boot with the patch. get winload.exe missing or corrupt message. ive used this patch many times on other systems so it wasnt operator or patch error.

just thought it would be worth a try in this situation to see if it changed anything.

#12 sixcentgeorge

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Posted 22 December 2016 - 08:04 PM

you can use the pae patch but there are two versions of this tool : one for win7 , one for win7 sp1 .

but with 4 Go there is not much to win

4Go being the max for x86 aka 32 bit ...take it easy and enjoy your pc ;']






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