[nilram]

A friend uses a saws-all (or something of that ilk) and cuts them in half. I'm figuring on taking my old drives to him for that treatment. I don't want to resell them and have a casual snooper recover my data, and I'm not of enough interest for anyone to piece the halves together.

[Symbiote]

What's the risk from simply writing over the drives with zeros, and sticking them in the electronics recycling?

I don't think anything I or my employer has would be worth the effort to recover.

[topspin]

This is what NIST says about it[1]:

    Advancing technology has created a situation that has altered previously held best practices
    regarding magnetic disk type storage media. Basically the change in track density and the
    related changes in the storage medium have created a situation where the acts of clearing and
    purging the media have converged. That is, for ATA disk drives manufactured after 2001
    (over 15 GB) clearing by overwriting the media once is adequate to protect the media from
    both keyboard and laboratory attack.

That's an elaborate way of saying that zeroing a healthy modern disk is sufficient. No need to break out the crucible or jackhammers. If you really need to indulge your paranoia then use some wiping system that does multiple overwrites with random data. It's not necessary, but at least you won't put your eye out.

[1] http://nvlpubs.nist.gov/nistpubs/Legacy/SP/nistspecialpublic...

If the device isn't healthy and can't zero all of the media then you will need to resort to physical destruction.

[abrookewood]

Yep. You can over write it once with zeroes (or random) and you are done.

[AnIdiotOnTheNet]

Right? What are the people in this thread doing that they're worried someone would take the time to employ theoretical, if not entirely hypothetical, recovery methods against a zeroed disk?

[golem14]

Zeroing out a 4tb drive takes some time. Sometimes you might be in a hurry ;)

[AnIdiotOnTheNet]

That's fair, but that doesn't explain the people talking about 10 pass overwrite routines and other such nonsense.

[bluedino]

I use a drill or press at work to do the same thing. Bens s drive in half or put a couple holes in the platters

[Johnny555]

Someone once suggested to me drilling a hole through the platters, then using that hole to fill the drive with salt water.

I don't know if the salt water really adds to security, but for the type of data on my drives, just drilling the hole seems like more than enough - no one is going to spend $1000 to recover my 2014 tax return from my drive since there are far easier ways to get my personal data.