Volatile vs Non-volatile Memory: What's the Difference?

PCs are made up of many components, and memory plays a key role in how everything works together. There are plenty of technologies to get your head around, whether it’s how double data rate memory works, the Differences between DDR5 and DDR4, setting the right speed for your RAM modules, or how hard drives store the ones and zeroes that make up your data.

A more fundamental concept to understand is the difference between volatile and non-volatile memory. Volatile memory loses its data when the power is off, while non-volatile memory retains it. Volatile memory demands a continuous supply of power, as it constantly refreshes the ones and zeroes it holds. Even a brief interruption in power will cause it to lose its contents.

The best example of volatile memory is RAM. SSDs and hard drives fall into the non-volatile category. Importantly, volatile memory is orders of magnitude faster than non-volatile storage, which is why we use both in our systems: RAM for speed, and SSDs (or hard drives) for long-term storage.

As shown in the table above, volatile memory is more expensive than non-volatile storage. And while RAM prices have dropped significantly over the years, SSD pricing has followed a similar downward trend. That’s why the classic combo of a small chunk of speedy RAM paired with a healthy slab of SSD remains the go-to setup. And yes, you can have a lot more RAM than that, and far bigger SSDs and hard drives, but the general idea still holds.