HDD questions.

1. Does HDD RPM give one an advantage in heavy multitasking?

2. Does the formatting of a HDD absolutely remove all previous data? At the risk of sounding vague, I hear that, when you think you are permanently deleting something from a HDD, there are still traces of the files or programs left. Is that the case with formatting as well? I asking because I would like to sell some HDD's that I don't need anymore.

 

1) Yes. Faster RPM drives (7200rpm vs 5400rpm) means faster seek times and transfer rates, both of which contribute to better multitasking performance. The measurement for multitasking performance is IOPS (I/O's per second).

However, as long as you're sticking with mechanical hard drives, you're talking about double-digit percentage increases in IOPS, at best. If you really want to multitask, then look into getting an SSD. A fast mechanical hard drive gets somewhere in the neighborhood of 500-600 IOPS. A fast SSD gets somewhere in the neighborhood of 35,000 - 40,000 IOPS, almost two orders of magnitude faster (10,000%).

Check out this video for an extreme example of multitasking on an SSD.
YouTube - Why I love my SSD - Windows 7 boot + loading 27 applications in about 1 minute.

Real world example of when this would be helpful:
You're installing an application in the background, and you're browsing the web while waiting. Your web browsing will be impacted, because your hard drive IOPS are already maxed out from the application install.

2) Yes and no.

If you do a quick format or regular format of your drive, then the only way to read the contents of the drive is to run specialized software to recover that data. It is possible to do, but not something that any regular person or even your typical techie will be interested in doing.

If there is someone out there whose specific intent is to recover data off of old hard drives, then a simple format will not be enough. There are several tools out there that will basically write and re-write blank data (all 0's) to your hard drive over several different passes, which will remove the ability for someone to recover the old data. The US Government uses these kinds of tools on hard drives that they decommission, to eliminate the possibility of someone recovering that data. If you are interested in going this extreme route, then let us know, and we can help you.

 

For number 2, most of what you delete in a simple format is easily recoverable with free software you can download, just like if you delete items from the recycle bin.

However, if you do a full format, it will write 0's to the entire drive. In this case, no data is recoverable from the drive at all, unless the platters are carefully removed and examined under an electron microscope or possibly some other extravagant way. So yeah, you are 100% safe with a full format. All these things like DBAN are just for grins and giggles because when the drive writes a 0, afterward it can only ever read a 0 from that location. The drive isn't capable of determining what was previously there.

 

First, thank you very much for your detailed answers.

Second, would you personally think twice about selling used, simple formatted HDD's locally (such as through craigslist), or do you think I would not have anything to worry about, unless I were extremely unlucky?

Thanks!

 

I really doubt anyone you would sell a hard drive to would have any malicious intent, but it is better to be safe than sorry. It isn't very hard to do a full format. Even if all you have is laptop with one hard drive bay and no external enclosure, you can still do a full format by inserting the OS disk and selecting a full format from there.

 

I wouldn't worry about it. I have sold hard drives to people before using a Windows format, without any reservations.

Another question you need to ask yourself - is there really any data on your hard drive that is worth someone going through the trouble of trying to recover and make sense of it? In most cases, people will answer no. Nobody really gives a crap about an email I wrote to a girlfriend two years ago, or even a credit card statement that you saved onto your disk.

 

Or hook up your hard drive to an Apple computer, run disk utility and run at least a 7 pass wipe (will take a few hours). There is a ton of free software that can recover data just by quickly formatting it. Or 35 pass wipe if you are absolutely paranoid about your data.