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 dfghjk 05-02-2004 01:09 AM

high vs low density ram

where can I find a good explaination of 64x8 high density ram vs 64x64
low density raam?

thanks

 why? 05-02-2004 03:44 AM

Re: high vs low density ram

On Sun, 02 May 2004 01:09:57 GMT, dfghjk wrote:

>where can I find a good explaination of 64x8 high density ram vs 64x64
>low density raam?

www.google.com

Roughly, if the sums below are correct for 445am. The chips that make up
a modue can come in several combinations of which can all appear to be
the same size.

Compatability of modules, depends somewhat on chipset in the
motherboard. Thats why the manual must be read carefully.

64M x 8bits = 64Mbits x 16 chips = 128Mbytes.
32M x 16bits = 64Mbits x 16 chips = 128Mbytes.

64M x 64bits = 4096Mbits x 8 chips = 512Mbytes then x16 chips i.e.
doublesided module is 1024Mbytes.

Some chipsets can't address higher density chips say those of 8 x 256 on
a single sided module, but will work fine with 16 x 128.

Me

 dfghjk 05-02-2004 12:59 PM

Re: high vs low density ram

OK, I still don't have it.

64Mx8 is called high density because .....

and 64Mx64 is low density because ....

it seems like 64Mx8 is a 64M chip with an 8bit (1 byte) wide data bus
which would require 8 chips for 512 MB.

and a 64Mx64 chip would be 64 bits wide and would require 1 chip for
512 MB, which seems like a higher density.

what am I missing?

I can understand why one chipset can address only one of these, I just
don't understand the physical arrangement.

On Sun, 02 May 2004 03:44:46 GMT, why?
<fgrirp*sgc@VAINY!Qznq.fpvragvfg.pbz> wrote:

>
>On Sun, 02 May 2004 01:09:57 GMT, dfghjk wrote:
>
>>where can I find a good explaination of 64x8 high density ram vs 64x64
>>low density raam?

>
>www.google.com
>
>Roughly, if the sums below are correct for 445am. The chips that make up
>a modue can come in several combinations of which can all appear to be
>the same size.
>
>Compatability of modules, depends somewhat on chipset in the
>motherboard. Thats why the manual must be read carefully.
>
>64M x 8bits = 64Mbits x 16 chips = 128Mbytes.
>32M x 16bits = 64Mbits x 16 chips = 128Mbytes.
>
>64M x 64bits = 4096Mbits x 8 chips = 512Mbytes then x16 chips i.e.
>doublesided module is 1024Mbytes.
>
>Some chipsets can't address higher density chips say those of 8 x 256 on
>a single sided module, but will work fine with 16 x 128.
>
>Me

 dfghjk 05-02-2004 03:11 PM

Re: high vs low density ram

WAIT - the module configuration for 512MB are ALL 64Mx64. The
difference is in the chip which can be 64Mx8 or 32Mx16 or 32Mx8.

this means the data bus is 64 bits (8 Bytes) wide

none of the block diagrams I have found show any difference in the
inputs to the module. All have 13 address bits muxed to 13 Rows, 11
Columns and 4 bank bits with 64 data bits out/in.

I think the memory sellers are trying to confuse the issue. My manual
makes no distinction between the TYPE of chips on the module. High or
Low density. Only 1024M max memory and 128, 256, or 512M modules. 64
bit data bus. 2.5CL PC2100 7.5ns.

So what does the high/low density have to do with anything??????????

On Sun, 02 May 2004 03:44:46 GMT, why?
<fgrirp*sgc@VAINY!Qznq.fpvragvfg.pbz> wrote:

>
>On Sun, 02 May 2004 01:09:57 GMT, dfghjk wrote:
>
>>where can I find a good explaination of 64x8 high density ram vs 64x64
>>low density raam?

>
>www.google.com
>
>Roughly, if the sums below are correct for 445am. The chips that make up
>a modue can come in several combinations of which can all appear to be
>the same size.
>
>Compatability of modules, depends somewhat on chipset in the
>motherboard. Thats why the manual must be read carefully.
>
>64M x 8bits = 64Mbits x 16 chips = 128Mbytes.
>32M x 16bits = 64Mbits x 16 chips = 128Mbytes.
>
>64M x 64bits = 4096Mbits x 8 chips = 512Mbytes then x16 chips i.e.
>doublesided module is 1024Mbytes.
>
>Some chipsets can't address higher density chips say those of 8 x 256 on
>a single sided module, but will work fine with 16 x 128.
>
>Me

 why? 05-02-2004 08:53 PM

Re: high vs low density ram

On Sun, 02 May 2004 15:11:12 GMT, dfghjk wrote:

>WAIT - the module configuration for 512MB are ALL 64Mx64. The
>difference is in the chip which can be 64Mx8 or 32Mx16 or 32Mx8.

Right, ignore modules it's the chips on the modules.

>this means the data bus is 64 bits (8 Bytes) wide
>
>none of the block diagrams I have found show any difference in the
>inputs to the module. All have 13 address bits muxed to 13 Rows, 11
>Columns and 4 bank bits with 64 data bits out/in.

It's the lump called 'address' that's how many row and banks. So high is
128x4 and low is 64x8.

>
>I think the memory sellers are trying to confuse the issue. My manual
>makes no distinction between the TYPE of chips on the module. High or

Not if the chipset doesn't support high density like KT400 / KT600.

>Low density. Only 1024M max memory and 128, 256, or 512M modules. 64
>bit data bus. 2.5CL PC2100 7.5ns.

Same on several mobo manuals I have, no distinction between low/high
only single/double sided modules. Although I can use 1024M modules the
manual doesn't say so it must be assumed it's low density.

>So what does the high/low density have to do with anything??????????

You have to look at the actual chips used, a 1GB module can use chips of
256Mx4 / 128Mx8 / 64Mx8 an extra pin is used for A13 for 16K rows,
column addresses are same as 512M.

The SPD , ID's the number of rows/column addresses.

Have you searched for any of the JEDEC docs on this?

>
>On Sun, 02 May 2004 03:44:46 GMT, why?
><fgrirp*sgc@VAINY!Qznq.fpvragvfg.pbz> wrote:
>
>>
>>On Sun, 02 May 2004 01:09:57 GMT, dfghjk wrote:
>>
>>>where can I find a good explaination of 64x8 high density ram vs 64x64
>>>low density raam?

>>
>>www.google.com
>>
>>Roughly, if the sums below are correct for 445am. The chips that make up
>>a modue can come in several combinations of which can all appear to be
>>the same size.
>>

<snip>

Me

 dfghjk 05-03-2004 12:45 AM

Re: high vs low density ram

On Sun, 02 May 2004 20:53:15 GMT, why?
<fgrirp*sgc@VAINY!Qznq.fpvragvfg.pbz> wrote:

>
>On Sun, 02 May 2004 15:11:12 GMT, dfghjk wrote:
>
>>WAIT - the module configuration for 512MB are ALL 64Mx64. The
>>difference is in the chip which can be 64Mx8 or 32Mx16 or 32Mx8.

>
>Right, ignore modules it's the chips on the modules.
>
>>this means the data bus is 64 bits (8 Bytes) wide
>>
>>none of the block diagrams I have found show any difference in the
>>inputs to the module. All have 13 address bits muxed to 13 Rows, 11
>>Columns and 4 bank bits with 64 data bits out/in.

>
>It's the lump called 'address' that's how many row and banks. So high is
>128x4 and low is 64x8.
>

Then for a 512MB module 64Mx8 chips are HIGH and 32Mx16 chips are LOW
????????????
Can LOW density be used where HIGH density is supported???
but if I have 32X8 chips on a 256MB module, does that make it a high
density module??

This just is still not jelling together.

>>
>>I think the memory sellers are trying to confuse the issue. My manual
>>makes no distinction between the TYPE of chips on the module. High or

>
>Not if the chipset doesn't support high density like KT400 / KT600.
>
>>Low density. Only 1024M max memory and 128, 256, or 512M modules. 64
>>bit data bus. 2.5CL PC2100 7.5ns.

>
>Same on several mobo manuals I have, no distinction between low/high
>only single/double sided modules. Although I can use 1024M modules the
>manual doesn't say so it must be assumed it's low density.
>
>>So what does the high/low density have to do with anything??????????

>
>You have to look at the actual chips used, a 1GB module can use chips of
>256Mx4 / 128Mx8 / 64Mx8 an extra pin is used for A13 for 16K rows,
>column addresses are same as 512M.
>
>The SPD , ID's the number of rows/column addresses.
>
>Have you searched for any of the JEDEC docs on this?
>

Tried that but haven't found anything worthwhile

>>
>>On Sun, 02 May 2004 03:44:46 GMT, why?
>><fgrirp*sgc@VAINY!Qznq.fpvragvfg.pbz> wrote:
>>
>>>
>>>On Sun, 02 May 2004 01:09:57 GMT, dfghjk wrote:
>>>
>>>>where can I find a good explaination of 64x8 high density ram vs 64x64
>>>>low density raam?
>>>
>>>www.google.com
>>>
>>>Roughly, if the sums below are correct for 445am. The chips that make up
>>>a modue can come in several combinations of which can all appear to be
>>>the same size.
>>>

><snip>
>
>Me

 why? 05-03-2004 07:53 PM

Re: high vs low density ram

On Mon, 03 May 2004 00:45:32 GMT, dfghjk wrote:

>On Sun, 02 May 2004 20:53:15 GMT, why?
><fgrirp*sgc@VAINY!Qznq.fpvragvfg.pbz> wrote:
>
>>
>>On Sun, 02 May 2004 15:11:12 GMT, dfghjk wrote:
>>
>>>WAIT - the module configuration for 512MB are ALL 64Mx64. The
>>>difference is in the chip which can be 64Mx8 or 32Mx16 or 32Mx8.

>>
>>Right, ignore modules it's the chips on the modules.
>>
>>>this means the data bus is 64 bits (8 Bytes) wide
>>>
>>>none of the block diagrams I have found show any difference in the
>>>inputs to the module. All have 13 address bits muxed to 13 Rows, 11
>>>Columns and 4 bank bits with 64 data bits out/in.

>>
>>It's the lump called 'address' that's how many row and banks. So high is
>>128x4 and low is 64x8.
>>

>Then for a 512MB module 64Mx8 chips are HIGH and 32Mx16 chips are LOW
>????????????
>Can LOW density be used where HIGH density is supported???

That's the impression I get.

>but if I have 32X8 chips on a 256MB module, does that make it a high
>density module??

Forget modules for a bit. The density is the depth of the addressing
'row/bank' for the chip.

i.e. (128M x 64 ) is 1 chip , it doesn't matter if it's 8 chips or 16
yet to form a module. If the 128M can't be addressed it's not of any
use for a mobo chipset without the correct support.

The high density stuff is getting into 1/2/4GB modules.

>
>This just is still not jelling together.

http://www.ordersite.com/canadaram/terms.htm
Density:
When a RAM module is built, the manufacturer can design it using high
density or low density chips. For example, modules built with 4 x 32Mb
chips, 8 x 16Mb chips or 16 x 8Mb chips all come out to the same amount
of RAM. However, the memory controller circuit in a computer must be
able to address the chips on the module - if the memory controller
cannot address higher density chips, that computer will only function
with modules built with lower density chips.

http://www.crucial.com/uk/library/128Mb_vs_256Mb.asp

http://www.kingston.com/tools/umg/umg04.asp

http://www.eepn.com/Locator/Products...892/28892.html

http://www.computing.net/hardware/ww...rum/24685.html

http://www.oempcworld.com/support/Hi...Lowdensity.htm

http://www.realworldtech.com/page.cf...0401204523&p=2

http://www.4allmemory.com/index.cfm?...ils&faq_id=102

>
>>>
>>>I think the memory sellers are trying to confuse the issue. My manual
>>>makes no distinction between the TYPE of chips on the module. High or

>>
>>Not if the chipset doesn't support high density like KT400 / KT600.
>>
>>>Low density. Only 1024M max memory and 128, 256, or 512M modules. 64
>>>bit data bus. 2.5CL PC2100 7.5ns.

>>
>>Same on several mobo manuals I have, no distinction between low/high
>>only single/double sided modules. Although I can use 1024M modules the
>>manual doesn't say so it must be assumed it's low density.
>>
>>>So what does the high/low density have to do with anything??????????

>>
>>You have to look at the actual chips used, a 1GB module can use chips of
>>256Mx4 / 128Mx8 / 64Mx8 an extra pin is used for A13 for 16K rows,
>>column addresses are same as 512M.

<snip>
>>>On Sun, 02 May 2004 03:44:46 GMT, why?
>>><fgrirp*sgc@VAINY!Qznq.fpvragvfg.pbz> wrote:
>>>
>>>>
>>>>On Sun, 02 May 2004 01:09:57 GMT, dfghjk wrote:
>>>>
>>>>>where can I find a good explaination of 64x8 high density ram vs 64x64
>>>>>low density raam?
>>>>
>>>>www.google.com

<snip>

Me

 dfghjk 05-03-2004 11:15 PM

Re: high vs low density ram

I THINK I FIGURED IT OUT!!!!!!!!!!!!!!!

NONE of the references actually make any sense. I don't think anyone
knows what the difference between high and low density is.

If my computer has a 256MB module with 32Mx8 chips than any module
with ??Mx8 chips will work. the key is the 8 bit wide not the 32M.
For me to go to a 512MB module it has to have 64Mx8 chips.
I can't read the chips on the 128MB module I have, but since there are
only 4 chips they have to be 32Mx8 chips also.

the other option is 64Mx4 chips, which to me would be LOW density and
you would need 16 of them which wouldn't fit on the module.. But high
and low density is all relative. Actually since there are 32Mx16
chips, you could say that mine is a MEDIUM density requirement.

The interesting thing is that compatibility has become such an issue
that suppliers are testing each module and label the exact same module
according to which system they test it in. That is why none of this
jells together.

this is for a Compac
http://www.memory-up.com/merchant2/m...BD32X8-RT-CEVO

this is for a Dell
http://www.memory-up.com/merchant2/m...32X8-RT-DI8285

M-266N-S512BD32X8-RT >>> the modules are identical

CEVO and DI8285 is the system tested in. (Compac EVO and Dell Inspiron
8200 & 8500)

the description "eight 64M x 8-bit (32M x 8-bit x 4 Bank /......)"
however makes no sense.
First it is a 64Mx8 chip and at the same time it is a 32Mx8 chip!!!

eight 32Mx8 x 4 bank chips = 256MB not 512MB - I already have one of
those.

eight 64Mx8 x 4 bank chips gives me 512MB.

SO what you are paying extra for is for someone to do an operational
test before they ship it to you. As an engineer that gives me no
confidence in the design of the modules or the system. If the specs
are the same and mirror the system requirements then why does one work
and the other does not????????????????????

thanks

On Mon, 03 May 2004 19:53:40 GMT, why?
<fgrirp*sgc@VAINY!Qznq.fpvragvfg.pbz> wrote:

>
>On Mon, 03 May 2004 00:45:32 GMT, dfghjk wrote:
>
>>On Sun, 02 May 2004 20:53:15 GMT, why?
>><fgrirp*sgc@VAINY!Qznq.fpvragvfg.pbz> wrote:
>>
>>>
>>>On Sun, 02 May 2004 15:11:12 GMT, dfghjk wrote:
>>>
>>>>WAIT - the module configuration for 512MB are ALL 64Mx64. The
>>>>difference is in the chip which can be 64Mx8 or 32Mx16 or 32Mx8.
>>>
>>>Right, ignore modules it's the chips on the modules.
>>>
>>>>this means the data bus is 64 bits (8 Bytes) wide
>>>>
>>>>none of the block diagrams I have found show any difference in the
>>>>inputs to the module. All have 13 address bits muxed to 13 Rows, 11
>>>>Columns and 4 bank bits with 64 data bits out/in.
>>>
>>>It's the lump called 'address' that's how many row and banks. So high is
>>>128x4 and low is 64x8.
>>>

>>Then for a 512MB module 64Mx8 chips are HIGH and 32Mx16 chips are LOW
>>????????????
>>Can LOW density be used where HIGH density is supported???

>
>That's the impression I get.
>
>>but if I have 32X8 chips on a 256MB module, does that make it a high
>>density module??

>
>Forget modules for a bit. The density is the depth of the addressing
>'row/bank' for the chip.
>
>i.e. (128M x 64 ) is 1 chip , it doesn't matter if it's 8 chips or 16
>yet to form a module. If the 128M can't be addressed it's not of any
>use for a mobo chipset without the correct support.
>
>The high density stuff is getting into 1/2/4GB modules.
>
>>
>>This just is still not jelling together.

>
>http://www.ordersite.com/canadaram/terms.htm
>Density:
>When a RAM module is built, the manufacturer can design it using high
>density or low density chips. For example, modules built with 4 x 32Mb
>chips, 8 x 16Mb chips or 16 x 8Mb chips all come out to the same amount
>of RAM. However, the memory controller circuit in a computer must be
>able to address the chips on the module - if the memory controller
>cannot address higher density chips, that computer will only function
>with modules built with lower density chips.
>
>
>http://www.crucial.com/uk/library/128Mb_vs_256Mb.asp
>
>http://www.kingston.com/tools/umg/umg04.asp
>
>http://www.eepn.com/Locator/Products...892/28892.html
>
>http://www.computing.net/hardware/ww...rum/24685.html
>
>http://www.oempcworld.com/support/Hi...Lowdensity.htm
>
>http://www.realworldtech.com/page.cf...0401204523&p=2
>
>http://www.4allmemory.com/index.cfm?...ils&faq_id=102
>
>>
>>>>
>>>>I think the memory sellers are trying to confuse the issue. My manual
>>>>makes no distinction between the TYPE of chips on the module. High or
>>>
>>>Not if the chipset doesn't support high density like KT400 / KT600.
>>>
>>>>Low density. Only 1024M max memory and 128, 256, or 512M modules. 64
>>>>bit data bus. 2.5CL PC2100 7.5ns.
>>>
>>>Same on several mobo manuals I have, no distinction between low/high
>>>only single/double sided modules. Although I can use 1024M modules the
>>>manual doesn't say so it must be assumed it's low density.
>>>
>>>>So what does the high/low density have to do with anything??????????
>>>
>>>You have to look at the actual chips used, a 1GB module can use chips of
>>>256Mx4 / 128Mx8 / 64Mx8 an extra pin is used for A13 for 16K rows,
>>>column addresses are same as 512M.

><snip>
>>>>On Sun, 02 May 2004 03:44:46 GMT, why?
>>>><fgrirp*sgc@VAINY!Qznq.fpvragvfg.pbz> wrote:
>>>>
>>>>>
>>>>>On Sun, 02 May 2004 01:09:57 GMT, dfghjk wrote:
>>>>>
>>>>>>where can I find a good explaination of 64x8 high density ram vs 64x64
>>>>>>low density raam?
>>>>>
>>>>>www.google.com

><snip>
>
>Me

 Peopleunit 07-10-2009 03:31 AM

High density versus low density just refers to the chip count on the memory module, high density modules use chips with a higher memory density per chip.

High density = 8 chips (one sided), low density is 16 chips (two sided).

------------------------------------------------------------------------------------------------------------

The spec numbers get confusing when one manufacturer's specs might refer to bits and another spec might be referring to bytes.

I.e., 32x64 generally means 32 mega bytes times 64 bits, 256MB total.

64 binary bits is the same thing as 8 bytes, and other manufacturers might use a spec structure of 32x8, where the 8 implies 8 bytes... 32M bytes x 8 bytes.

Another practice that leaves a lot of people confuses is bits versus bytes. A capital B is meant to mean BYTES, a lower case B refers to BITS. I.e., 32mb = 32m bits, and 32MB = 32m bytes.

 Operando185 11-01-2009 03:23 PM

Quote:
 Originally Posted by Peopleunit High density = 8 chips (one sided), low density is 16 chips (two sided).
[bump]

That can not be correct...

I have 2 banks lying here, both 512 MB RAM, PC133 (from Siemens, chips made by Infineon). They do not work in my old HP Vectra, that's running Xubuntu. The computer beeps in protest and will not boot.

They have 8 chips on both sides, so, a total of 16 chips. They must be (are) "high-density", since they do not work in aforementioned Vectra.

Right? :confused:

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