Salvaging Defective DRAM

An anonymous reader writes "Ever wonder what happens to DRAM that fails quality assurance testing during manufacturing? Turns out a lot of it ends up as 'downgrade' memory and ends up in OEM memory modules. Last resort: use it in an answering machine, where the sampled audio can be very tolerant of bit errors."

Comments

bad ram patch for linux

[Anonymous Coward]

Summary: This page proposes an approach to support RAMs with defective addresses, This may open interesting business perspectives, where those RAMs can be sold under a white label for less money rather than discarded of without any profit.

the url is:

http://rick.vanrein.org/linux/badram/

Use memtest86

[Black Parrot]

...and read its documentation to find out how to make Linux skip any defects it finds.

recycling the chips

[v1]

I recall seeing an article awhile ago where companies were buying defective memory, and running them in these external testing units,which would identify which chip(s) on the stick were bad. I'm assuming they'd then unsolder the bad chip and recover one from another module. At that time some of those sticks had 8 chips on each side, so you could recover 15 good sticks from 16 bad ones. Considering the price of memory a few yrs ago, it was probably a worthwhile venture. Nowadays though, it's probably not worth anyone's time.

Re:Buying ram on the internet.....

[sjames]

If only that was the worst of it.

Generic RAM is also in the habit of mis-reporting it's capabilities in SPD. The problem was so bad with 512M sticks back when that was the biggest available, many BIOS would automatically disregard SPD and choose the slowest settings when a 512M stick was detected.

Better brand names don't appear to have that problem.

Re:well

[wik]

Not to mention, give you hell at the airport. The security guys in Pittsburgh told me to put my keys in the little bucket, then when they looked closer, told me to put them through the X-ray machine.

They were looking at the old 256k SIMM PCB (all chips removed) and asking "is that a computer chip"? Funny how they pointed at that and missed my Intel keyring fob with a real processor die on it.