Windows XP reads my 1GB RAM as 504mb

Dell Dell optiplex gx280 desktop intel p...
August 10, 2010 at 13:58:01
Specs: Microsoft Windows xp professional w/service pack 3
I have 2 slots and they were both 256 mb (Came with pc) even then my pc only showed 502 mb of memory and so I got a new ram it was a 1gb ram so I replaced one of the 256mb rams with the 1gb ram still my pc showed 502 mb of ram and I even tryed to leave the 1gb ram in the pc alone with out a 2nd ram it still showed 502 mb I do not know why it does this because my computer reads it when it starts. But windows xp doesnt

Dell Optiplex Gx280 SFF
504mb Of Ram <-the problem
80gb hardrive
128mb graphic card



See More: Windows XP reads my 1GB RAM as 504mb

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#1
August 10, 2010 at 14:11:55
Some motherboards require RAM to be installed in pairs, so removing the 2 chips and replacing them with one means that the PC can't see all the memory there. To get the memory boost it may be that you need to have two chips installed, so 2x512 or 2x1024 etc etc.

Just a thought.


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#2
August 10, 2010 at 14:15:26
Thats not right because the ram i got with the pc is more then 502 but yet windows only reads 504 mb of ram

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#3
August 10, 2010 at 14:42:57
did u check shared memory? There is option used by dell systems which is "os installating mode" or similar. Look for it in bios (i assume this is bios info)

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Related Solutions

#4
August 10, 2010 at 15:22:03
I dont know how to get there please post to to get into there

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#5
August 10, 2010 at 15:37:37
Do any of u think me reinstalling windows can fix this ?

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#6
August 10, 2010 at 19:43:43
I suspect you have bought RAM with too high density chips on it.

According to crucial.com your board can accept up to 1GB of RAM in each slot. However, if 1GB it must have 8 128MB chips on it. Not 4 256MB chips on it.

Also, your board utilizes dual channel memory controllers.

What that means is you will get better performance from two identical sticks of 512MB instead of one stick of 1GB.

Count the chips on the RAM stick to see how many there are.


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#7
August 12, 2010 at 09:26:36
In response to your PM to me...

What it all boils down to is you bought a 1gb ram module that is NOT COMPATIBLE with being used in your mboard. If you bought it locally, take it back and get a refund.
If you bought it on the web, ship it back and get a refund.
However, you may not actually get a refund until the ram has been tested and found to be okay, and a fee may be deducted from the refund because you returned it and it wasn't their fault you bought the wrong one (re-stocking charge, etc.) . Shipping charges are not refundable, unless the seller specified the module you bought would definately work in your mboard.
......

You quote both 502 and 504mb as being the total amount or ram reported in Windows. I'm assuming 502mb is a typo, or you were quoting the wrong amount.

If you're quoting the right amount..
E.g. if you RIGHT click on My Computer - Properties - the total amount of ram reported by the mboard's bios is shown on the right on the first screen you see
.... then it was probably 504mb.

When you are using video built into the mboard - onboard video - some mboard bioses subtract the amount of ram that is being shared with the onboard video because it can't be used by the operating system for other uses, and if so, Windows reports that same amount.
In your case, the mboard's bios is subtracting 8mb at present.

Onboard video always uses/shares ram in certain even multiples, 2 to the x power, except for the first choice - e.g. 8, 16 (8 x 2; 2 to the first power) , 32 (8 x 4; 2 squared), 64 (8 x 8; 2 cubed) , 128 (8 x 16; 2 to the 4th power) , 256 (8 x 32; 2 to the fifth power), 512 (8 x 64; 2 to the sixth power), etc. mb
......

"I replaced one of the 256mb rams with the 1gb ram still my pc showed 502 mb of ram and I even tryed to leave the 1gb ram in the pc alone with out a 2nd ram it still showed 502 mb"

I'm assuming both 502s in that are supposed to be 504.
Onboard video can't use 10mb.
The 256mb module is probably not being detected at all when the 1gb is installed along with it. The 1gb module is being detected as 512mb, half of it's true size, minus 8mb for the amount of ram shared with the onboard video.
.....

"Do any of u think me reinstalling windows can fix this ?"

Windows has nothing to do with your problem.

The total amount of ram reported in Windows is determined by the mboard's bios.
When you're using onboard video, the bios may or may not subtract the amount of ram being shared with that onboard video from the total amount of ram dtected by the bios.

The amount of ram detected by the bios is correct only when you use ram modules that are all 100% compatible with being used in your mboard - in this case, compatible with what the memory controller in the main chipset on your mboard requires.

Gledsters info in Response 1 does not apply to your mboard.
.....

You DO NOT randomly buy ram.

Ram that works in another mboard , or any ram you buy or have lying around, may not work properly, or sometimes, not at all - even if it physically fits and is the right overall type (e.g. SDram, DDR, DDR2, etc.; PCxxxx, xxx mhz) for your mboard. In the worst cases of incompatibilty your mboard WILL NOT BOOT all the way with it installed, and the mboard may not even beep - the ram has to be compatible with the mboard's main chipset, or in the case of recent mboards, compatible with the memory controller built into the cpu.

See response 5 in this for some info about ram compatibilty, and some places where you can find out what will work in your mboard for sure:
http://www.computing.net/hardware/w...
Correction to that:
Mushkin www.mushkin.com

Once you know which module ID strings (part numbers) work in your mboard, you can get them from anywhere you like that has ram with those ID strings.

If you have brand name ram, it is usually easy to look up whether it's ID string (part number) is in a list of compatible modules found by using your mboard or brand name system model number.
If the ram is generic, that may be difficult or impossible.
.....

OtheHill said:

"I suspect you have bought RAM with too high density chips on it.

According to crucial.com your board can accept up to 1GB of RAM in each slot. However, if 1GB it must have 8 128MB chips on it. Not 4 256MB chips on it."
"Count the chips on the RAM stick to see how many there are. "

That may be what your problem is.

"I have 2 slots... "
"Dell Optiplex Gx280 SFF"

However, depending on where I look, 1gb or 2gb modules are specified as the max size you can install in your Gx280 small form factor series mboard, which has two ram slots.
(There is a mboard for the Gx280 minitower / desktop series that has 4 ram slots - that's NOT your mboard.)
Usually when various sources disagree about the max module size, the ones that state you can use larger modules have updated info and that info is correct.

E.g. for the Gx280 SFF (Small Form Factor) series...

Kingston specifies a 2gb max module size.
Go here:
http://www.ec.kingston.com/ecom/con...

Manufacturer: Dell
Model: Gx280 small form factor
Click on search
...

Crucial specfies a 1gb max module size.
http://www.crucial.com/store/listpa...

Corsair specifies a 2gb max module size.
http://www.corsair.com/configurator...

Memory Giant specifies a 1gb max module size.
http://www.memorygiant.com/memory/d...
.....

OtheHill said:

"Also, your board utilizes dual channel memory controllers.

What that means is you will get better performance from two identical sticks of 512MB instead of one stick of 1GB."

Your mboard can use either single channel ram, or dual channel ram, which is sold in matched pairs of identical modules of the same capacity, or, pairs of indentical single channel ram modules of the same capacity (size) can run in dual channel mode.
When your mboard has more than two ram slots, in order for all of it to run in dual channel mode, all the ram must be compatible with running in dual channel mode - each pair has to be in certain slots, each pair has to have identical sized modules but the pairs don't have to be using the same sizes of modules.
However, in the real world, having all your ram running in dual channel mode yields only a tiny improvement in performance of the ram - a few percent at best.


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#8
August 12, 2010 at 11:25:42
i didnt randomley buy one i got a ddr2 one and i made sure it was the right one

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#9
August 12, 2010 at 11:25:58
and ur right i ment 504

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#10
August 12, 2010 at 12:23:29
"I didnt randomley buy one i got a ddr2 one and i made sure it was the right one "

"Ram that works in another mboard , or any ram you buy or have lying around, may not work properly, or sometimes, not at all - even if it physically fits and is the right overall type (e.g. SDram, DDR, DDR2, etc.; PCxxxx, xxx mhz) for your mboard."

If you didn't use a ram configurator or similar to look up the specific ram modules listed for your Gx280 SFF model series, then you essentially randomly bought ram.

If it's any consolation, your problem is not unusual - - many people have bought or have tried to use the wrong ram, and we hear about problems similar to yours frequently.


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#11
August 12, 2010 at 13:09:08
You guys dont understand that the issue happens with the orignal ram my pc came with

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#12
August 12, 2010 at 13:16:27
You could try to install the 256MB in the first slot and the 1GB in the second. That may allow it to read the 256MB stick. That doesn't mitigate the fact that you have an incompatible stick of 1GB RAM.

Your 2 - 256MB will probably outperform the 760MB you might get when reversing the RAM.

Return the RAM and buy RAM from someone like crucial.com.

I suggest you reinstall both 256MB stick and then go to crucial.com and use their online scan tool to determine what type and how much RAM your board can run. They guarantee the RAM they recommend will work.

For best performance you want to install 2 stick of the same exact RAM so the two controllers can both run independently. That is called dual channel.


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#13
August 12, 2010 at 13:52:14
from what ive seen i have the right type

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#14
August 12, 2010 at 14:02:55
There are more specs than just the type, capacity and the speed. If you had the right RAM it would work. All I found on your computer states it can handle 1GB in each slot.

Did you try going to crucial.com? The capacity of the individual memory chips on the module is what the density issue is about.

Integrated memory controllers that were made prior the the increase in chip density either can't configure the RAM at all or configure it at half if the density is just twice the controller capacity. Hope this makes sense to you.


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#15
August 12, 2010 at 15:50:35
"You guys dont understand that the issue happens with the orignal ram my pc came with "

You said
"I have 2 slots and they were both 256 mb (Came with pc) even then my pc only showed 502 mb of memory "

That should be 504, when you're using onboard video that is sharing 8mb of the ram, and the bios subtracts the amount shared from the total.
There was probably nothing wrong initially - you just didn't understand why the bios was deducting 8mb from the total. The total amount of ram Windows reports is the same as the total the bios reports.

If the ram came with the PC when it was new, then it's compatible with being used along with any other modules that are listed as compatible.

If you didn't get the PC new, someone may have installed one or both modules that are not compatible with being used along with other modules that are listed as compatible, despite the fact they were recognized properly initially.

"from what ive seen i have the right type "

No, you don't.

OtheHill has done a pretty good job of explaining there is more to whether ram is compatible than just it's DDR speed and PCxxxx spec.

If you HAD picked a compatible 1gb module, the total reported ram amount in the bios and in Windows would be 1.25 gb - 8mb when a 256mb module and the 1gb module is installed, assuming the 256mb module is 100% compatible ( 1,024mb + 256mb - 8 = 1,272mb or 1.242gb), and 1gb - 8 mb when only the 1gb module is installed (1,024mb - 8 = 1,016mb or .992gb)

There are hundreds, if not thousands, of Topics on this site about other people who bought or have tried to use incompatible ram modules !


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#16
August 12, 2010 at 17:04:36
can you go into the bios setup utility? please look at how much memory the bios says is in the computer. also are you using on board video?

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#17
August 12, 2010 at 17:15:32
Tubes, some BIOSes have an option to load into memory. The BIOS may be anything from 1MB to as much as 4MB. In this case, I suspect the BIOS is 2MB and is being loaded into RAM. That would explain the 2MB difference. That plus 8MB to dedicated video.

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#18
August 12, 2010 at 18:00:30
He said in response 9
"and ur right i ment 504"

Older bioses have a setting "System Bios Cacheable" or similar. I always enable that. If that's enabled, it loads a few kb of data at most, not the entire bios contents, into spare space in the conventional first 1,024 kb. That doesn't affect the total ram amount reported at all.


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#19
August 12, 2010 at 19:08:52
Ok guys ill try to get a diffrent ram and use the site u gave but i used the site and asked live chat if I have the right ram and they said I do

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#20
August 12, 2010 at 19:18:01
New update i went on my bios and they asked me for video card to take 1mb or 8mb of memory from system it was on 8mb so i changed it to 1mb but ram was still on 504mb of ram

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#21
August 12, 2010 at 19:22:33
Did you save bios settings and reboot?

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#22
August 12, 2010 at 19:25:46
yes i did and one of my friends whos good with pcs said it might be the motherboard is messed up

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#23
August 12, 2010 at 19:34:26
I don't think 1MB is a valid option for shared memory on a modern system. 1MB will only allow VGA (640 x 480) 16 bit color.

Anyway, is this with the 1GB stick of RAM or the 2 original 256MB sticks?


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#24
August 12, 2010 at 19:44:35
right now im useing the 256 2 sicks

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#25
August 12, 2010 at 20:32:01
There is nothing wrong with that RAM. I don't know what integrated graphics you have but chances are it can use more than 8MB. If you want, try upping the shared RAM to see if the 504 number falls.

How many memory chips are on the new 1GB stick?
What is printed on each of the chips?


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#26
August 16, 2010 at 10:32:03
This is probably not the answer but I do believe in some cases if you have an integrated graphics card it takes away some of the memory for its own use.

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#27
August 16, 2010 at 11:41:24
sammygunns

If you want to contribute to the threads here, kindly read the entire thread. Your comments were already mentioned multiple times.


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