# [SOLVED] Hgh or Low density memory



## Louie1 (Oct 14, 2013)

I am trying to upgrade memory. I have purchase some DDR2 PC2-6400 2GB memory modules to accomplish this task. I am being told by the vendor that they are low density. However, there is no manufacture stated on the memory, so I cannot contact them to ask. I do not know much about memory and have seen this type of question a lot, but have not found the answer I need.
I know that having chips on both sides of the module does not necessarily mean that the module is low density. My question is this: If the module ONLY has chip on one side can it still be low density?
The vendor states that they are made with "low density" chips??? I thought that "density" had to do with how the memory was arranged, not the type of chips.


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## Tyree (May 10, 2009)

*Re: Hgh or Low density memory*

Brand & Model of the Mobo you want to install the RAM in?


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## greenbrucelee (Apr 24, 2007)

*Re: Hgh or Low density memory*

chips on one side would indicate single sided memory chips on both sides double sided, it has nothing to do with density.

If you could tell us your computers specs or model number then I could tell you if your system is supposed to take low/high density please read this link MythBUSTED: Density FACTS - Low Density vs High Density | eBay


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## Louie1 (Oct 14, 2013)

*Re: Hgh or Low density memory*

I am not sure where the MB info would be, I do not usually go this deep. The Computer is an HP DC7900 SFF desktop. I have upgraded 5 of these DC7900 machines so far (with the same memory modules mentioned previously - purchased at the same time). The sticker on the MB states:
PAVFE0SSUYA4LJ
SP#462432-001
DG#460970-000

On the outside, the computer label:
SN# MXL0030QYW
Prod #NE150UC#ABA
d79008S/Q9400/61051/7k US

The 2Gb memory modules that came in the machine (happen to have chips on both sides) and are Hyinx HYMP125U64CP8-S6 AB-C.
I first installed one new module and received a 5-beep code. I tried the new memory alone (in case of incompatibilities). Same result. I then went through all remaining 6 modules. 4 of which gave me the 5-beep codes and no boot. 3 did boot (w/ one of the original memory modules in the black slot).
I was confused about the memory, since they worked in the other machines and was leaning to the fact that maybe they weren't really low density and the other machines possiblly had later dated MBs and had accepted the memory. I assume that if I had low density then my chances of a successful upgrade would be greatly improved (approaching 100%).


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## Tyree (May 10, 2009)

*Re: Hgh or Low density memory*

Your PC is an OEM model so the best option is to use Crucial brand RAM to avoid compatibility issues.
A 2x2GB matched pair of DDR2 DDR2 PC2-6400(non-ECC) should be plenty.
Mixing RAM brands/specs commonly results in problems. A matched pair will help avoid that problem.


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## Louie1 (Oct 14, 2013)

*Re: Hgh or Low density memory*

Thank you very much for your quick replies. I did not know what to expect. I have read many forums but have not submitted questions until now.

Your solution to memory selection is great, I appreciate your getting at the base issue, but that was not really my intent with my question. I had Crucial part numbers for memory, by running their online memory scanner before I posted the question.

My question had more to do with identifying High density memory. From the follow-up post, I mentioned that I have successfully used this memory in 5 other of the same machines but now it does not work in this one. I am looking to upgrade more of them and I have this memory on hand.

Is there any way to know if the memory is high density / low density other than taking the vendors word for it? I mean obviously, the mother board knows somehow.

I also know that low density memory is not 100% compatible with all MoBo, maybe this is one of those.

Again, thank you for your time and quick responses.


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## Tyree (May 10, 2009)

*Re: Hgh or Low density memory*

Any RAM listed on the the Crucial site for your Mobo will be correct.
Did you read the link supplied by greenbrucelee?


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## Louie1 (Oct 14, 2013)

*Re: Hgh or Low density memory*

Yes, I did read greenbrucelee's reply. I had found that also before I posted. That is where I first saw the mention of single side / double side, but it did not correlate that with a possible low/hi density connection, so my question remained. Then I decided to post my question.

He has not replied since I put the part number info on the reply. I do not know if those listed are the sought after part numbers. He may be able to tell me "ok, your MoBo needs low density". But what I have is "supposedly" low density and the majority of them give 5-beep codes and no boot. I am just trying to understand, I guess.


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## greenbrucelee (Apr 24, 2007)

*Re: Hgh or Low density memory*

you cant really tell if some ram is low or high density by looking at it, if your buying this ram from somewhere like ebay just google the model number on the manufacturers page and the manufacturers web site will confirm it.


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