SDRAM Compatability Tricks Wanted

[KrazyKid]

I have tried 3 times to use "generic" or "housebrand" DIMMS and they are 256Mb/PC133 but when they post on my system they always post at 128Mb...I know the answer that most will want to reply..."Buy The Good Stuff!!" But I have specific questions I would like to have answered...

I have seen disclaimers by some dealers such as:
"For VIA KT266/A,KT-133/A,KX-133 SIS 630,AMD 751 Iron Gate VIA Apollo 133A Pro,VIA 694 Chipsets ONLY"
or "High Density - For Newer mboards"

What I want to know is if you have the DIMMs in hand, how can you tell what they actually are.


High Density?
Low Density?
Unbuffered?
Buffferd?
Registered?
UnRegistered?
ECC?
NONECC?
Only for a specific motherboard chipset/CPU combo?



Please offer as much information as possible.
Also please post any URLs that I can reference for further info!

Thanks in advance!

 

[Crashman]

Higher density memory may or may not work on your system, depending on the BIOS, chipset, and motherboard construction. This was first noted on Intel VX chipset boards that could not use memory of more than 2MB per chip, so that a 16 chip module was always read as 32MB. Most newer chipsets can handle 32MB/chip. Some handle only 16MB/chip.

Some boards also don't like double sided DIMMs.

Buffered memory is actually a different type and fits only slots made for it. It will only work on systems designed for it, most likely none of yours.

ECC memory has an extra parity bit for every byte of information, used for error correction. If you install it, you must also enable ECC in BIOS to use this feature. ECC can make your system a little more stable, but slows it down slightly. It's used mainly in machines that need a higher degree of accuracy, such as in science applications.

Most registered memory is ECC, I've never seen any that wasn't. Some DDR systems require Registered memory in order to use all four slots. People who need registered memory but don't want ECC can turn the ECC off in BIOS.

Your board is probably limitted to a lower density than what you have, try a lower density.

What's the frequency, Kenneth?

 

[siliconjon]

As for how to tell what you have in hand, registered sticks out because of how tall it is, and the extra little chips near the leads. To figure out if it's high density, you must know the size of the dimm, then devide that by the number of chips, and you will get the amount per chip. I don't think there have been any buffered chips since EDO ram...I could be mistaken (perhaps some mini-computers use it or something).

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