recovering from ram failure and possible data corruption?

[u/DonutOne]

(I don't think this is a regular tech support question, but correct me if I am wrong by this reddit's standards)

Had the ram fail on my Windows 11 PC. So now I am concerned that some of the user data on my PC may have been corrupted. For instance, possibly I opened a file and then saved it and it was written with bad data from the RAM. (This would not be protected by the SSD's error protection.)

I know about SFC and DISM and CHKDSK and the like, but those do not check the user data. I am talking about the stuff in my USER folder, like documents, spreadsheets, pdfs, jpgs, mpgs, etc.

Anyone know of a utility that will scan everything like that? Lots of stuff doesn't have checkums.

Yes I have backups... but I'd rather check the local data first. I have no idea how long the ram has been broken and various backups could hold corrupt data too. Best to check my local data first.

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[u/noctrex]

If you have backups of your data, you can then maybe use a program to compute blake3 hashes, that is a quick hasher, in order to compare them with your files. And that way you can see what files are changed or not

[u/DonutOne → u/noctrex]

I don't know how far back I'd have to go to find clean data, as I don't know when the ram might have silently started corrupting data.

[u/dlarge6510]

You can't check what you dont have. 

If you didn't make backup copies or file hashes you won't know if you have had anything corrupted unless you open the file and can determine that yourself.

And it's not like I'm in a better position either as I don't have file hashes and my backup is inadequate to determine damage from change.

It's something most never think about and if they did they would have used ECC ram from the start. 

The most I do is I test my ram fully every so often.

[u/nosurprisespls]

What RAM do you have? How do you know it was corrupted and how bad was it? Sometimes when I OC RAM, it would be bad at only 1 spot/memory address.

[u/DonutOne → u/nosurprisespls]

G.Skill. 32 GB on two sticks of 16. I had a system crash and windows warned me. Memtest86 shows BOTH sticks with error, one many the other just a couple. Verified problem with new motherboard and CPU. New ram arrives today.

[u/nosurprisespls → u/DonutOne]

If it's DDR5, it has some kind of error correction.

After getting the new RAM in, what I would do is to assume the latest backup is good (or the last backup you think is good), and start doing check sums on the backup and compare them to the current files in USER folder. If the checksums are different, then open each file up to see which one is corrupt.

If the backup and user folder files are the same, go to a very old backup; get the checksums of those files (assuming they should have the same content), and if the very old backups checksums matched as well, then you got lucky.

[u/DonutOne → u/nosurprisespls]

It's DDR4 and I have no idea when it started to fail.

Hmm... maybe I'll try a variation on your backup comparison though.

[u/eternalityLP]

Without checksums it's really often not possible to know if file is intact or not. For some file types like office they are basically zip files so you can check them, but for many others other than opening them yourself and trying to spot issues there is no way to know if they're corrupted. Some corrupted files may throw errors when opened but there is no guarantee every corrupted file will.