Well RAM is going bad on my computer that i dont use much anymore and really don't need fancy RAM for. So on my quest on looking for new ram i saw High Density RAM, cheaper but made by off brands, and usaully no warrenty (wich doesn't bother me).

So while trying to find more out about this High density RAM on google i really couldn't dig up any good topics about what it clearly does and what it CLEARLY works with! It says what it has been tested to work with !

Well thats nice but i wish there was somting describing what it wants to work and how a motherboard determines if it can use it or not.

I have a ABIT NF-7 S v2.0 I have looked at ABIT's site for a answer on capable RAM but maybe im just not looking close enough because i don't see were it says anything about High Density RAM.

Here is the compadability test ...

Compadability test

If you know anything more about it i would really like to know ! I don't know much about it and am a little bit curious about how excally it works.

This post has been edited by Mr.Chow: May 14 2006, 02:50 AM

Article from a memory sellers site.

It costs memory manufacturers almost the same to produce Low Density modules which have 100% compatibility with all systems on the market, comparing to producing high density modules. So why would manufacturers be so foolish to produce high density modules which only have 10% compatibility with systems on the market? The reason is simple, because high density modules are mainly manufacturing process rejects/seconds that cannot be made as a low density modules. It is very much like Intel CPU, those CPU that cannot be made as Pentium 4 CPU become a slower bus Celeron CPU instead, by a down-binning process.

In short:-
LOW DENSITY modules have 100% compatibility with ALL systems and ALL chipsets.
HIGH DENSITY modules only have 10% compatibility.

SRX660

Ok thats a start then. Thank you for that. It was short and mostly to the point.

BUT

How can you actully check for compadability on a motherboard ?

Easiest way is the crucail website they tell you what ram is compatible.

As near as I can figure, my Asus P3V4X motherboard should support what a dealer is calling 'high density' PC133 512 Mb SDRAM on a 168 pin board. The memory works just fine at 66 MHz, and the BIOS sees all 2Gb. Ditto at 100 MHz. At 133 MHz, BIOS recognizes all 2 Gb, POST runs fine, everything is groovy, until an operating system starts to load. Then the system becomes unstable, sometimes rebooting.

From what I have read, if the memory is incompatible due to density, either the system won't boot, or the BIOS only recognizes 1/2 of the RAM. I haven't seen anything about the system being stable at slow FSB speeds, but not at 133 MHz. But I have seen where a system will operate fine on PC100 memory at 100 MHz, but become unstable at 133 MHz.

All of this leads me to think that what I have been sold are actually 4 PC100 512 Mb DIMMs, instead of PC133.

Any comments, suggestions, tests, experiences?

If I RMA the memory, how likely is the seller to put them in a PC133 machine and see if they work? Is there a fool-proof, absolutely certain method of determining the speed rating of no-name, no number DIMMs?