What causes memory errors?

[tgxiii]

This is really odd... the last three RAM sticks I've used in this one build has gotten tons of errors. The first two were 256MB Mushkin Basic PC2700 sticks and the third one was a 512MB Corsair Value Select PC3200.

I used Memtest86 to test the sticks before installing Windows XP. They came out clean with no errors. After a while, the BSOD would appear. I then re-checked the sticks and discovered a bunch of errors. What would cause the errors to appear?

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Abit KD7A
AMD Athlon XP 2500+ Barton
256MB Prolink Pixelview GeForce FX 5600
Enermax 330w PSU
80GB Maxtor ATA/133 8MB Cache

2x256MB Mushkin Basic PC2700 at first, then
512MB Corsair Value Select PC3200
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[Bovon]

There are several reasons for errors to pop up with ram modules...some will be ram transistors going bad and others may be DIMM sockets flaky and/or a flexed motherboard while installing the RAM and damaging the circuit traces.

I had a motherboard a couple of years ago that kept crashing the system, and when I ran memtest, it found ooodles of bad memory, but since this happened to every stick of ram I had in that particular board, I began to retest the RAM modules in other mainboards..guess what..no errors in a different board.

But, if the problem does turn out to be the RAM itself, it is probably some of the transistors in the chips going bad..too much voltage on the RAM modules maybe?..killing the chips?..

A RAM chip has hundreds (thousands?) of transistors...the data that passes thru a RAM module/chip is binary..meaning a word or number will use several different transistors to turn on or off, supplying a 1 or a 0 as necessary. If the chip is bad, and a 1 is held at 0..that gives us an error.

[tgxiii]

The voltages are set at default. I haven't tested the Corsair stick on another board yet, but I did check the Mushkin sticks on another board and errors still showed up.

Maybe the motherboard does something that causes the sticks to get errors?

[Defero01]

A lot of errors on memory chips are caused by hotspots on the memory module, caused either by improper air circulation or improper voltage, when a memory module developes a hot spot the transistors lose the ability to properly store data.

[tgxiii]

Anyone have a guess as to what's causing the problem? PSU? Mobo?

[bailey]

bad ram ?

[tgxiii]

Thanks for telling me something I already didn't know, bailey.

[bailey]

I was serious.
mishandeling of the ram can distroy it before it even gets into the motherboard.
not taking proper care with ESD can and will distroy ram before it is even installed

[John Prophet]

Ask Peter M..I remember he was fairly certain that a high % of the ram being sold had defects etc.

[jmichna]

Up the vDIMM +0.20 or +0.30 and see if the errors disappear. My experience is all ram seems to benefit (in terms of stability) from some extra voltage (not just the cheap stuff, too). Even +0.30 will not hurt DIMMs over an extended period of time... several years on a particular build, in my experience.