solid state drives

Securely Erasing SSDs

If you’re about to sell or give away a computer, it’s important to ensure that all of your personal data is erased first. This is a pretty simple task when it comes to traditional spinning hard drives, and there are plenty of tools to make sure the drive is completely and securely wiped. Solid State Drives, however, are a different story. SSDs use something called “wear leveling,” which ensures that no one cell gets written to too many times. This is to keep the drive from wearing out, but it also means that it isn’t possible to write over (or erase) every part of the drive.

What's the difference between a traditional hard drive and a solid state drive?

Michelle from Northridge, CA

Episode 1450

Leo says that all traditional spinning hard drives are basically the same. They're basically like record players, but instead of vinyl, they use spinning metal plates. Those plates are magnetic, so they can be magnetized. They also have read heads, at least one per platter, which are like the needle on the record player. Except instead of reading the grooves in vinyl, they're reading the magnetic signals coming off the spinning platter. Because it's a computer, everything is recorded as 1's or 0's, and it's very easy with magnetic material to have a charge or no charge.

What's the difference between a traditional hard drive and a solid state drive?

Michelle from Northridge, CA

Episode 1407

Leo says that all traditional spinning hard drives are basically the same. They're basically like record players, but instead of vinyl, they use spinning metal plates. Those plates are magnetic, so they can be magnetized. They also have read heads, at least one per platter, which are like the needle on the record player. Except instead of reading the grooves in vinyl, they're reading the magnetic signals coming off the spinning platter. Because it's a computer, everything is recorded as 1's or 0's, and it's very easy with magnetic material to have a charge or no charge.

What to Look for When Buying a Hard Drive

Since hard drives have become a mature technology, the differences between them are more trivial. However, there are several models that are best for certain tasks. Depending on what the drive will be used for, rotation speed, reliability, storage capacity, and power consumption, may be important factors. But the most dramatic differences are between Hard Disk Drives and the newer Solid State Drives.

Can I boost my SSD performance with AHCI?

Jeff from Oklahoma

Episode 1052

Jeff just installed an SSD into his Lenovo desktop, but he can't enable AHCI (Advanced Host Controller Interface). Leo says it's in the kernel, but it doesn't mean it has to be enabled. Leo suggests using native mode since Jeff only has one drive anyway. He'll get the best performance he can for SATA 2, but he'll still have a speed improvement over the old hard drive.

How can I secure data on my SSD?

Kyen from San Jose, CA

Episode 1032

Kyen has been hearing that an SSD cannot be securely erased. Leo says that is correct. No matter what you do to wipe the drive, it's always best to use the built in encryption technology of Mac or Windows, or even the utility that comes with the drive. Even when overwriting the SSD 13 times, someone will be able to pull the data from it, in theory. In reality, nobody really has the technology to get all the data back, though. But some fragments will always remain. This also applies to smartphones and tablets. This makes encryption even more important.