How to identify if a module is LOW or HIGH density?

[XistenZ]

I just recently become aware of this term, density. A memory module can be either low or high density, meaning the amount of chips attached to it. However it's not as simple as just counting them (so called IC's), simply put the only one who knows if a module is low or high density is the manufacturer themselves.

Am I completely wrong about this? I can't find an answer to my problem "how to identify if a module is low or high density".

Some more backstory: I have a dell motherboard, it'll only accept low density modules which I found out by wondering why two identical modules, spec-wise, only one of them worked but the other didn't. I contacted Corsair (the modules's manufacturer) and asked about these specific modules, they confirmed one is high and the other is low density).

I propose to start a list where we list all modules we know is low or high density, until someone figures out a way to know anyway or if the manufacturers will just come out and tell us... Because it's quite unpleasant not being able to order RAM you don't know is going to work. We need all info!
I'll start with the two modules I tested.

***Corsair***
CMZ8GX3M2A1600C9 (kit 2x4GB, 240-pin DDR3, 1600MHz, cl9, 1.5v) - low density
CML8GX3M2A1600C9 (kit 2x4GB, 240-pin DDR3, 1600MHz, cl9, 1.5v) - high density

 

[brispuss]

Density is related to the amount or capacity of memory locations on memory chips (memory depth (memory locations per bank x number of banks) x data width).

To determine density (and compatibility) requires additional information from memory manufacturers ie memory chip depth (locations/bank x banks) and data width be added to memory specifications. Unfortunately most memory manufacturers do not provide this information (yet).

I have contacted several memory manufacturers so far (directly or via forums) to request that memory chip configuration details be added to memory specifications to enable a better idea of memory density and compatibility.

Amount of Density is relative, with respect to the two memory modules being compared.

Examples -

1) One module uses 256 Mb chips, while another module uses 512 Mb chips. The Low Density memory here would be the module with the 256 Mb chips, and the High Density memory would be the module with the 512 Mb chips.

2) One module uses 1 Gb chips, while another module uses 2 Gb chips. The Low Density memory here would be the module with the 1 Gb chips, and the High Density memory would be the module with the 2 Gb chips.

So, it would be preferable to list the actual memory chip configuration (memory depth x data width x number of chips used on module) instead of trying to determine which chips are High Density and which chips are Low Density.

 

[XistenZ]

If modules would be high/low density only compared to one another, how can motherboards (such as Dells) determine which module is low? It doesn't really know which one of the two I'm gonna put in there, now does it?

If low and high density is only for "US", it wouldn't really matter but some motherboards just won't accept high density and that's why such information is needed.

And of course adding more info such as amount of ICs and their numbers would be a good thing. The more you know the better, but the modules I listed so far is covered by heaters, and I'm not going to dissect them just to have a peek

 

[brispuss]

The terms High Density and Low Density relating to memory are arbitrary/subjective, there is no "rule" as such to say whether memory is either High or Low Density. It is up to the individual to decide what is what. Dell or whoever have just applied their judgement as to what is High and what is Low Density memory. Their interpretation may not match other peoples' interpretation.

It is the actual chip configuration which aids in determining compatibility and not the arbitrary terms High and Low Density. One might say a module using 512 Mb chips is High Density, but another might label it as being Low Density; that is not useful for other people. This is therefore too subjective, and open to misinterpretation.

Dell (and whoever else) should have instead referred to chip configuration details instead of using the terms Low and High Density memory, since they did not specify what their interpretation of High and Low Density memory is/was.

Because of this subjectivity, it is better to have chip configuration details made available instead. This information is factual and there can be no misinterpretation.

 

[XistenZ]

Thank you brispuss, I think you have given the best answer on the internet about what low/high density really is.
I'll stop chasing this information, and just accept the manufacturers "compatible" memories, instead of finding a better alternative based on knowledge, as it seems impossible.

 

[brispuss]

That is wise! And you are welcome!

 

[lada_]

Thank you so much brispuss! Your answers resolve a great deal of confusion over what to know in adding memory to my Dell XPS 8930.

I bought crucial, following instructions in another thread, that it is most compatible with my device.
However, I did not grok that the 16GB I purchased would require some mental prowess re determining whether it is alright to use with my 8GB that came installed with the XPS 8930 last July. (I've adding memory to other computers in the past).

After some time clarifying the meaning of the crucial online support member's slightly cryptic replies, I finally got this answer: the number of chips on the back of my new memory stick need to be the same number as on the installed memory stick.

The manual also states "put the highest density module in bank 0".
I also used crucial's application on their website to choose from the memory stick's compatible with my current computer. One does hope that app is accurate!

Since this thread has the dates 2015, I've no idea if anyone will catch my question. Essentially, I am 'asking' about that counting the number of chips on the back of the memory stick as useful data for this compatibilty of memory sticks?

Thank you sincerely and respectfully.
lada_