# my memory is 512 but it only reads 128



## trebor11584 (Dec 6, 2006)

guys, hopw you can help me with my problem... i just bought a memory SDRAM 512mb PC-133, i thought it would work just fine until I inserted it and test, when my PC boots it only reads 128 instead of the 512. i would like to know what's causing this problem... hope anyone can help me


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## PanamaGal (Jun 3, 2006)

What motherboard do you have?


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## trebor11584 (Dec 6, 2006)

PanamaGal said:


> What motherboard do you have?


thanx for reading this i attach my motherboard specs which is generated using everest and cpu-z test.


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## crazijoe (Oct 19, 2004)

Can you put it in a zip file?


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## PanamaGal (Jun 3, 2006)

I'm with crazijoe, a zip format would help.


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## crazijoe (Oct 19, 2004)

I found a program to open it.
This is a PIII setup with a motherboard that uses the Intel 440BX chipset. Your BIOS date is 6/13/00. 
They are a few reasons why you cannot see the full amount of memory. 

First. The 440BX chipset will only support 256MB max in each slot. On top of that, the modules must be double rank (low density). Meaning the motherboard is capable of supporting 1GB not exceeding 128MB per rank (4 slots / 256MB x 4).

Second. If indeed you are using a double rank module (low density) you may need to upgrade the system BIOS. Native 440BX boards could only support up to 128MB in each slot. But I believe that you BIOS is current enough to support 256MB in each slot.

I am going to have to conclude that the reason you are only seeing 128MB is because the module you have is a 512MB high density (single rank) module. Which in turn means that since your MB will only see 128MB per rank, that is all you will see out of the module.

You sould probably check about returning the stick and get a couple of low density 256MB modules. 

http://www.techsupportforum.com/


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## Done_Fishin (Oct 10, 2006)

Here are the basic points from the Everest report.




> Motherboard:
> CPU Type Intel Pentium IIIE, 866 MHz (6.5 x 133)
> Motherboard Name DFI CB50-BX/ZX / CB60-BX/ZX / CB61 / P2XBL Rev D / PB50-BX/ZX / PB61-ZX
> *Motherboard Chipset Intel 82440BX/ZX *
> ...





> DMI:
> DMI BIOS Vendor Award Software International, Inc.
> DMI BIOS Version 4.51 PG
> DMI System Manufacturer
> ...





> Memory Controller ]
> 
> Memory Controller Properties:
> Error Detection Method 8-bit Parity
> ...



From Intel
http://www.intel.com/support/motherboards/desktop/sr440bx/sb/cs-013647.htm


> Main Memory
> 100MHz 3.3V SDRAM DIMMs
> 512 MB maximum main memory
> Two DIMM slots


http://www.intel.com/design/support/faq/embed_proces/pentiumiii_lp_mod.htm


> *What kind of SDRAM clock buffer should I use with the 440BX?*
> Zero delay clock buffers have internal PLLs which cause contention with the PLL internal to the 440BX. This contention can be observed in the form of jitter on the 440BX DCLKO and DCLKWR signals. As another observable symptom the system will lockup after the processor attempts to fetch the first 8 bytes of BIOS. *The customer should use SDRAM clock buffers that do not have an internal PLL.*
> 
> *Are 256Mbit SDRAM's supported?
> ...


From what i have seen from both French & Dutch forums (by searching for DFI CB50-BX/ZX in Google) max board size is 256MB Double sided. ie 128MB per side
If your memory is 512 single sided then it will only recognise 128MB


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## crazijoe (Oct 19, 2004)

Done_Fishin said:


> From what i have seen from both French & Dutch forums (by searching for DFI CB50-BX/ZX in Google) max board size is 256MB Double sided. ie 128MB per side
> If your memory is 512 single sided then it will only recognise 128MB


Try not to use the term "single sided" or "double sided" as it is not actually liable anymore. I have seen high density (single rank) modules that are double sided.



> First rule, Double sided memory is not always low density modules. High density modules can have 16 chips (8 on each side). 'Standard' RAM chips are organized a DEPTH x 8 Bits. E.g. 32x8, 64x8, etc. That means 8 of the chips make up a 64 bit wide rank (memory bus is 64 bits wide). "Double Sided" is an old term to describe a stick with 16 chips, 8 on each side. And with DEPTH x 8 chips that makes for 2 ranks (or, again in an older style terminology: 2 'banks').
> 
> 'High Density' chips are DEPTH x 4 bits so it takes 16 to make a 64 bit wide memory rank. And this is why "double sided" is no longer the favored description because when x8 chips are used "Double sided" means "double rank" but with x4 chips it takes both sides and 16 chips to make the ONE, single, rank.


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## Done_Fishin (Oct 10, 2006)

I thought that it only applied to newer technolgy (ie P4 style mobo's) and that older mobo's like PIII were still classified as single / double sided especially since we are talking 133MHz. 

Old habits die hard :grin:

seems we were answering at the same time, and at least we agree! regardless of how we phrase it. :4-cheers:


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## crazijoe (Oct 19, 2004)

The 440BX chipset is where I discovered this long ago on my Gigabyte GA-BX2000+ MB. I had come across a 256MB stick that was double sided but was high density. It would only show as 128MB. I noticed the chips were 16x4 chips. It took 16 chips to make the 64bit memory bus therefore the chips were on both sides but arranged in a "single rank". 

For a 256MB "low density" module you need to make sure that the chips, on the module, are 16x8.


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## Done_Fishin (Oct 10, 2006)

Good Point to note .. maybe I was just lucky


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## trebor11584 (Dec 6, 2006)

crazijoe said:


> I found a program to open it.
> This is a PIII setup with a motherboard that uses the Intel 440BX chipset. Your BIOS date is 6/13/00.
> They are a few reasons why you cannot see the full amount of memory.
> 
> ...


thanx for answering my post, regarding on the uploaded file it can be open using winrar it can be found on www.rarlab.com but i guess you don't need this any more, back to the topic i have a few questions again to ask here it is:

1. regarding to you conclusion, what would i do now? ask the store to replace the memory for 2 256mb SDRAM? is that what you mean? and if "yes" what specification would i look for the replacement to run properly (to maximize the capacity) on my mobo? 

2. do i still need to update my BIOS? and if ever where can i find the latest update? does my mobo supports more than 512 of memory?

3. lastly, i'm not too techie to understand some terms you are using like "high density" and "low density", but i'm trying to understand the topic you posted. so in regard with that, i'm describing my memory. it has 8 chips on both sides so what will i term it high density or low density?

hope you can find the time to answer my queries, and sorry for my bad english... more power


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## crazijoe (Oct 19, 2004)

1. Yes I would ask the store to replace the memory with 2x 256MB low density modules. Since the 512MB module is not compatible with your system. Ask the seller for "Low Density" or "Double Rank" modules. Make sure the chips read 16x8 and not 16x4 or 32x4. 

2. You probably do not need to update your BIOS. If you do, this is not a task that can be taken heartedly, because if done incorrectly, it will render the motherboard useless. BIOS update can be downloaded from the MB manufacturer. How ever you will need the exact model number of your motherboard to get the right BIOS version. If you flash the wrong version, it could render your motherboard useless.

3. When you have chips on both sides, the term "double sided" is usually used. As I stated above, you really cannot use this term any more to identify "high density" or "low density" modules. You really need to look at the individual chips on the module and see their arrangement. 

The memory bus is 64 bit wide. You need sufficient number of chips on the module to make this 64 bit wide bus. On a 256MB stick, if they are using 16x4 chips, then it will take 16 chips to make the 64 bit bus. Each rank needs enough chips to make 64bits.


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## trebor11584 (Dec 6, 2006)

crazijoe said:


> 1. Yes I would ask the store to replace the memory with 2x 256MB low density modules. Since the 512MB module is not compatible with your system. Ask the seller for "Low Density" or "Double Rank" modules. Make sure the chips read 16x8 and not 16x4 or 32x4.
> 
> 2. You probably do not need to update your BIOS. If you do, this is not a task that can be taken heartedly, because if done incorrectly, it will render the motherboard useless. BIOS update can be downloaded from the MB manufacturer. How ever you will need the exact model number of your motherboard to get the right BIOS version. If you flash the wrong version, it could render your motherboard useless.
> 
> ...



for the forum:

hi guys, thanx for the answer in my querie... i reuploaded the file again coz the details that everest generated was incomplete coz its just a trial version, i uploaded the complete generated output of everest so here it is... i just hope you can analyze it again. i have one question regarding my memory again, according to the report of everest the module size of my memory is it has (1 rank, 4 banks) or 512MB, the question is can you tell if my memory is low or high density base on the info i gave you? coz according to your answer in my recent post that my memory is high density... i just want to make sure, im sorry if i ask a lot of the same question, i just want to make it clear to me coz im not that techie by nature, and the one that you're discussing is new to my ears i hope you have a lot of patience to me... and sorry for my english. hope you can answer this again


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## Done_Fishin (Oct 10, 2006)

I've been looking around the DFI site looking for your mobo.

I can find the numbers given in the report, I cannot fina any mobo with 4 DIMM slots. most have 2 a few have 3. I looked at Socket 370 and Slot1 styles without joy.
CAn you look at your mobo, verify how may slots DIMM slots available in case it's a question of the "interpretation" by the interrogating s/w.
All boards I have seen indicate max memory 512MB.

CB50-ZX
http://sj.dfi.com.tw/Product/xx_product_spec_details_r_us.jsp?PRODUCT_ID=1155&CATEGORY_TYPE=null


> Specification
> CPU
> Celeron™ 300A-466MHz or future 100MHz FSB Celeron™ Processors
> 
> ...



CB60-ZX
http://sj.dfi.com.tw/Product/xx_product_spec_details_r_us.jsp?PRODUCT_ID=1157


> Specification
> CPU
> Celeron™300A-466MHz or future 100MHz FSB
> Celeron™Processors
> ...


OF course NONE of this info fits in with your mobo specs 



> Motherboard:
> CPU Type *Intel Pentium IIIE, 866 MHz (6.5 x 133) *
> Motherboard Name DFI *CB50-BX/ZX* / *CB60-BX/ZX */ CB61 / P2XBL Rev D / PB50-BX/ZX / PB61-ZX
> Motherboard Chipset Intel 82440BX/ZX
> ...


Are you overclocking ???


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## trebor11584 (Dec 6, 2006)

Done_Fishin said:


> I've been looking around the DFI site looking for your mobo.
> 
> I can find the numbers given in the report, I cannot fina any mobo with 4 DIMM slots. most have 2 a few have 3. I looked at Socket 370 and Slot1 styles without joy.
> CAn you look at your mobo, verify how may slots DIMM slots available in case it's a question of the "interpretation" by the interrogating s/w.
> ...


thanx for reading,nope im not overclocking ....the processor multiplier is set to default, i never want to try to overclock...its too risky, on your question...my board contains 3 DIMM slots, why are you asking? is there somethinng wrong with my mobo?


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## Done_Fishin (Oct 10, 2006)

NOthing Wrong

was looking at your Report.html
which said


> [ Memory Devices / DIMM1 ]
> 
> Memory Device Properties:
> Form Factor DIMM
> ...


so I had been loking to find a mobo with 4 DIMM slots but there aren't any.
Also the CPU clock speed that is supported is supposed to be a lot slower than you 866MHz.


I suspect that you have the PB50-BX board or a clone ..

http://sj.dfi.com.tw/Product/xx_pro....jsp?PRODUCT_ID=1224&CATEGORY_TYPE=MB&SITE=US



> PB50-BX Features
> 
> Overview
> 
> ...


It could be this board but it's a slot1
P2BXL R D


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## Kalim (Nov 24, 2006)

Or maybe this? *CB50-BX Rev.1*










Any of these CB50-ZX, CB60-BX, CB60-ZX?


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## Kalim (Nov 24, 2006)

Done_Fishin said:


> I've been looking around the DFI site looking for your mobo.
> 
> I can find the numbers given in the report, I cannot fina any mobo with 4 DIMM slots. most have 2 a few have 3. I looked at Socket 370 and Slot1 styles without joy.
> CAn you look at your mobo, verify how may slots DIMM slots available in case it's a question of the "interpretation" by the interrogating s/w.
> ...


Maybe its this instead, with 3 DIMMS.

DFI® GCB50-BX Motherboard 

:4-dontkno ?


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## Kalim (Nov 24, 2006)

From what I've seen, your mobo supports 768MB RAM at maximum in three slots of 256MB max each.


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## Done_Fishin (Oct 10, 2006)

AT DFI they only show the mobo's with 2 DIMMS

http://sj.dfi.com.tw/Product/produc...&CATEGORY_NAME0B=Socket+370&SITE=US&offset=10



> VIA 82C694T and VIA VT82C686B CA64-TC ATX Audio and ATA100,Suspend to RAM
> 
> VIA 82C694T and VIA VT82C686B CA64-TN ATX Celeron 1.2 GHz+, Audio and ATA100
> 
> ...


If its ITOX it must be a clone 



> DFI® GCB50-BX Motherboard Product Information
> Features:
> 
> • Long and stable product life cycle
> ...


But the mobo we are talking about is supposedly supporting 866MHz CPU and 133MHz Memory


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## Kalim (Nov 24, 2006)

Hmm, I came across all that and couldn't make sense of it unless its overlocked from 656 up to 866.


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## Done_Fishin (Oct 10, 2006)

says he isn't overclocking and I belive him. Of course I have put a higher a Higher speed CPU in a mobo but run it at default speed, it says its the 600MHz but runs at less, this could be the situation. When I tried running it at overclocked speeds I got problems, so I backed down to 66MHz bus.
What confuses me is the 133MHz, since it shouldn't be an option.


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## Kalim (Nov 24, 2006)

Thats exactly why I'm confused - I was thinking it should be 100MHz.. unless overlocked. 
Lets see if its 866/133 = 6.51 multiplier
Left to that @ 100 x 6.5 = 651MHz CPU 

Maybe closer to the range that the mobo's are offering here. If I keep the multiplier the same but lower the memory bus:

66 x 6.5 = 429MHz

I don't know but I know I can't find this motherboard at all but in a version with a lower spec. I still think that his max per slot is 256MB and that he should stick to that.


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## Done_Fishin (Oct 10, 2006)

Kalim said:


> I don't know but I know I can't find this motherboard at all but in a version with a lower spec. I still think that his max per slot is 256MB and that he should stick to that.


agreed, that's where we came in ...:grin:


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## Kalim (Nov 24, 2006)

Still haven't managed to find anything matching


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## crazijoe (Oct 19, 2004)

The 440BX chipset is capable at running 133MHz FSB only in overclocking mode. It will work and is stable however this is not the native FSB speed and you run into complications with PCI devices.


> according to the report of everest the module size of my memory is it has (1 rank, 4 banks) or 512MB


The key to this answer lies within the question. 

(1 rank, 4 banks)

You only have a single stick of memory and it is occupying a single slot. If it was a Low Density module it would say (2 ranks, 4 banks). Since the chipset will only accept 256MB per slot, technically it will only accept 128MB per rank. Which is the max for a 440BX chipset.


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## Kalim (Nov 24, 2006)

Would it accept a total of 256Mb in one rank in any one slot?


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## crazijoe (Oct 19, 2004)

Kalim said:


> Would it accept a total of 256Mb in one rank in any one slot?


No, You would need a 256MB double rank module. It will only see 128MB in a single rank.


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## trebor11584 (Dec 6, 2006)

crazijoe said:


> No, You would need a 256MB double rank module. It will only see 128MB in a single rank.


i would like to ask, how can i identify a low density modules or how will i know if its 16x8 chips by just looking at them? because some stores just sell memory and sometimes they doesn't know what are the specifications of the product they are selling, so as a consumer i would like to know how will identify the memory i'm looking for in case the seller doesn't know. and lastly, i would like to know how can i identify a bad memory to a memory who just doesn't read its full capacity like in my case?


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## crazijoe (Oct 19, 2004)

Most the time the chips will be individually marked "16x8" or "32x4" etc.. If the seller does not know if the module is high density or low density, ask them if they guaranty it will work in your specific machine. Or ask them if it does not work if you can receive a full refund. If they do not, then do not buy. Like I've said before. It's better to spend more and get the correct product than spend a little and hope it works. If you want a module that is guaranty to work in your machine, buy from memory experts like Crucial or 4AllMemory. They may charge a little more but the extra cost is better then the headache of getting the wrong memory.



> i would like to know how can i identify a bad memory to a memory who just doesn't read its full capacity like in my case?


Bad memory will be just plain bad. No partially good or some of it not working and reading the full amount. You can test for faulty memory with diagnostic programs. I use memtest86 and Window Memory Diagnostic. I use both programs because one will be better than the other in some areas and vise versa. 
As far as what your motherboard supports, read the manual.


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