How to test and safely keep using your janky RAM without compromising stability using memtest86+ and the memmap kernel param.
Dealing with faulty RAM modules in 2026
https://blog.kumio.org/posts/2026/01/memtest86plus.html
https://blog.kumio.org/posts/2026/01/memtest86plus.html
How to test and safely keep using your janky RAM without compromising stability using memtest86+ and the memmap kernel param.
11 Comments
TheHolm@aussie.zone · 8 pts · 219d
Imho not worth the risk. Nothing except ECC is protecting system from memory corruption. And consequences of flipped bit can be huge. Unless it is in a system you do not care about, just do not use it.
Tetsuo@jlai.lu · 6 pts · 219d
Very cool to be able to do that even though I'm not sure it's worth it to run a RAM module that has a known defect.
If the fault spreads there will be corruption again.
kumi@feddit.online · 6 pts · 219d
There is one part in the post mentioning how to "pad holes" in failing areas. Maybe I should expand it with some details around aligning reserved address space.
Otherwise, corruption of the RAM itself does not usually spread like mold in bread or wear out and fail in similar ways to flash memory.
Tetsuo@jlai.lu · 3 pts · 219d
By spreading I meant thar if there is an underlying manufacturing defect it would be really difficult to predict where and when it would happen on memory. And if there is already a fault detected more might come later.
But I'm glad you documented how to do these types of workaround. It might be helpful with memory prices skyrocketing...
Passerby6497@lemmy.world · 4 pts · 219d
I tried this for a bit last year, and I never got it to work. I'm sure it was user error, but I'm super glad I got a new kit before shit blew up.
Might have to track down the bad kit I had and give this another try for giggles.
user1234@lemmynsfw.com · -4 pts · 219d
First rule in computer building is to always buy twice as much RAM as you actually need so you can just remove the bad stick when this happens
muusemuuse@sh.itjust.works · 5 pts · 218d
Second rule of computer building is just keep the receipt until after it passes 40 minutes of memtest. Third rule is to ignore rule one, nobody does that.
kumi@feddit.online · 5 pts · 218d
I always heard the first rule as "stay grounded". Having 1TB of RAM on stock just in case sounds not grounded.
A spare kit or two should be enough for most folks. With one or two spares of everything else so you can test suspicious parts separate from prod.
A bit of redundancy and foresight is good but no need to be excessive about it.
user1234@lemmynsfw.com · 1 pts · 218d
Needing 1TB of RAM is far outside the standard case.
muusemuuse@sh.itjust.works · 3 pts · 218d
Well he technically only need 512 gigs but had to double it because some dude on the internet said so.
kumi@feddit.online · 2 pts · 218d
OK, so let's cut it down and say we have 4 PCs for someone with a family and home server, with 4 DIMMs each.
You are saying the first rule of PC building says that this house should have at least 16 unused DIMMs on the shelf. I'd say 2-4 is reasonable if they are all compatible.
"Buy two extra of everything" is a good rule and scales for the individual. "Buy double of everything" is not.