Portable SSDs are a good way to increase the amount of storage you have to preserve digital data and take that data with you wherever you go. These powerful accessories let you pack a huge amount of storage in your daily bag, giving you a place to offload files from your computer or smartphone, a place to access files you only need in certain circumstances, and backup important information on the go.

But the world of portable SSDs is a large one, and deciding on the best device for your needs can be a challenge. It’s not just about how small the device is, how durable it is, or how many gigabytes of storage it has—the speed of a portable SSD can heavily influence your satisfaction with it. SSDs in general promise better read and write speeds than HDDs, so you’ll see a general increase if you’re going from one to the other. However, not all portable SSDs perform the same—even if they advertise similar maximum speeds.

To help you decide which portable SSD may work for you, Ars put some of the newest and most popular portable SSDs on the market to the test and judged them on speed, design, durability, compatibility, and price. Here are our findings: