What’s the Diff: RAM vs Storage

By | January 15th, 2019

WHATS the DIFF? RAM vs Hard Drives

Perhaps the most common challenge computer users encounter when using a computer involves memory, or the lack thereof in their computer.

Computer support technicians will tell you that computer users are often unclear on the different types of memory in their computer. Users often interchange memory with storage, and vice-versa. Statements like “I have eight gigabytes of disk,” or “I have one terabyte of memory” tell computer support people that they’re dealing with a novice when it comes to computer terminology.

We don’t want you to appear as a novice, so let’s break the concepts down and examine these two parts of your computer, how they work together, and how they affect your computer’s performance.

The Difference Between Memory and Storage

Your computer’s main memory is called RAM. You can think of it as a workspace the computer uses to get work done. When you double-click on an app, or open a document, or, well, do much of anything, RAM gets used to store that data while the computer is working on it. Modern computers often come equipped with 4, 8, 16 or more gigabytes of RAM pre-installed.

There’s also storage: a hard disk drive or solid state drive where data is recorded and can stay indefinitely, to be recalled as necessary. That might be a tax return, a poem in a word processor, or an email. By comparison, RAM is volatile — the information that’s put in there disappears when the power is turned off or when the computer is reset. Stuff written to disk stays there permanently until it’s erased, or until the storage medium fails (more on that later).

What is RAM?

RAM takes the form of computer chips — integrated circuits — that are either soldered directly onto the main logic board of your computer or installed in memory modules that go in sockets on your computer’s logic board.

RAM stands for Random Access Memory. The data stored in RAM can be accessed almost instantly regardless of where in memory it is stored, so it’s very fast — milliseconds fast. RAM has a very fast path to the computer’s CPU, or central processing unit, the brain of the computer that does most of the work.

RAM is random access as opposed to sequential access. Data that’s accessed sequentially includes stuff that’s written to your hard disk drive, for example. It’s commonly written in files, with a specific start location and end location. We’ll get to your hard drive storage in a moment.

If you have general purpose needs for your computer, you probably don’t need to tweak its RAM very much. In fact, depending on what computer you buy, you may very well not be able to change the RAM. (Apple and others have removed RAM upgradability from some of their lower-end or portable computers, for example).

Mojave About Dialog BoxHow much RAM on Mac OS (Apple Menu > About This Mac)

How much RAM -- Windows 10

How much RAM on Windows 10 (Control Panel > System and Security > System)

If your computer is older and upgradable, putting in more RAM helps it load and use more apps, more documents, and larger files without slowing down and having to swap that data to disk, which we’ll cover below.

If you work with very large files — big databases, for example, or big image files or video, or if the apps you work with require a large amount of memory to process their data, having more RAM in your computer can help performance significantly.

What is Computer Storage?

Computers need some form of non-volatile storage. That’s a place data can stay even when the computer isn’t being used and is turned off, so you don’t have to reload and re-enter everything each time you use the computer. That’s the point of having storage in addition to RAM.

Storage for the vast majority of computers in use today consists of a drive, either a hard drive or a solid state drive. Drives can provide a lot of space that can be used to store applications, documents, data and all the other stuff you need to get your work done (and your computer needs to operate).

Mac OS Disk SpaceDisk Space on Mac OS (Apple Menu > About This Mac > Storage)

Windows 10 Disk Space

Disk Space on Windows 10 (This PC > Computer)

No matter what type of drive you have, storage is almost always slower than RAM. Hard disk drives are mechanical devices, so they can’t access information nearly as quickly as memory does. And storage devices in most personal computers use an interface called Serial ATA (SATA), which affects the speed at which data can move between the drive and the CPU.

So why use hard drives at all? Well, they’re cheap and available.

In recent years, more computer makers have begun to offer Solid State Drives (SSDs) as a storage option, in place of or in addition to a conventional hard disk drive.

SSDs are much faster than hard drives since they use integrated circuits. SSDs use a special type of memory circuitry called non-volatile RAM (NVRAM) to store data, so everything stays in place even when the computer is turned off.

Even though SSDs use memory chips instead of a mechanical platter that has to be read sequentially, they’re still slower than the computer’s RAM. That’s partly because of the performance of the memory chips that are being used, and partly also because of the bottleneck created by the interface that connects the storage device to the computer – it’s not nearly as fast as the interface RAM uses.

How RAM and Storage Affect Your Computer’s Performance


For most of us using computers for general purpose work — checking email, surfing the web, paying the bills, playing a game or two and watching Netflix — the RAM our computer comes with is as much as we’ll need. Further down the road, we might need to add a bit more to keep up with new operating system improvements, updated apps, and new apps that have a heftier memory requirement.

If you’re planning to use your computer for more specialized work, more RAM may benefit you greatly. Examples of those sort of tasks include editing video, editing high-resolution images, recording multi-track audio, 3D rendering, and large scale computations for science and engineering.

Again, depending on what computer you buy, you may not be able to upgrade your RAM. So consider this carefully the next time you buy a new computer, and make sure it’s either upgradeable or comes equipped with as much RAM as you think you’ll need.

Your computer’s RAM can fill up: load up a bunch of applications, open a bunch of documents, get a bunch of activities going, and RAM will be used up by each of the individual processes, or programs, that are running.

When that happens, your computer will temporarily write information it needs to keep track of to a predefined portion of your hard drive or SSD. This area is called virtual memory, and swapping data from RAM to disk is a standard feature of modern operating systems.

The faster your disk is, the less time it takes for the computer to read and write virtual memory. So a computer with an SSD, for example, will seem faster under load than a computer with a regular hard drive.

SSDs also take less time to load apps and documents than hard drives, too. Really, if your computer is using a hard drive, one of the best things you can do to extend its life and improve performance is replace the hard drive with an SSD.


Besides RAM, the most serious bottleneck to improving performance in your computer can be your storage. Even with plenty of RAM installed, computers need to write information and read it from the storage system — the hard drive or the SSD.

Hard drives come in different speeds and sizes. Many operate at 5400 RPM (their central axes turn at 5400 revolutions per minute). You’ll see snappier performance if you can get a 7200 RPM drive, and some specialized operating environments even call for 10,000 RPM drives. Faster drives cost more, are louder and use more power, but they exist as options.

New disk technologies enable hard drives to be bigger and faster. These technologies include filling the drive with helium instead of air to reduce disk platter friction, and using heat or microwaves to improve disk density, such as with HAMR (Heat-Assisted Magnetic Recording) and MAMR (Microwave-Assisted Magnetic Recording).

Because they use computer chips instead of spinning disks, SSDs are faster still, and they consume less power, produce less heat, and can take up less space. They’re also less susceptible to magnetic fields and physical jolts, which makes them great for portable use. They’re more money per gigabyte (though the price has dropped quite dramatically in recent months), so do what you will based on your budget and your needs.

For more about the difference between hard drives and SSDs, please check out Hard Disk Drive Versus Solid State Drive: What’s the Diff?

Adding More Disk Storage

As a user’s disk storage needs increase, typically they will look to larger drives to store more data. The first step might be to replace an existing drive with a larger, faster drive, or, if space permits, to add a second drive. A common strategy to improve performance is to use an SSD for the operating system and applications, and a larger HDD for data if the SSD can’t hold both.

If more storage space is needed, an external drive can be added, most often using USB or Thunderbolt to connect to the computer. This can be a single or multiple drive and might use a data storage virtualization technology such as RAID to protect the data.

If you have really large amounts of data, or simply wish to make it easy to share data with others in your location or elsewhere, you likely will turn to network-attached storage (NAS). A NAS device holds multiple drives, typically uses a data virtualization technology such as RAID, and is accessible to anyone on your local network, and, if you wish, on the internet, as well. NAS devices can offer a great deal of storage and other services that typically have been offered only by dedicated network servers in the past.

Back Up Early and Often

No matter how you configure your computer’s RAM and hard drive, remember to back up your device. Whether you have an SSD or a hard drive, and regardless of how much RAM is installed, things will eventually slow down and stop working all together.

You don’t want to be caught without any sort of ability to recover. That’s why it’s vital to have a backup strategy in place. A good backup strategy shouldn’t be dependent on any single device, either, so even if you’re backing up to a local hard disk, a network attached storage system, a Time Capsule or some other device on your computer or local network, you’re not doing enough. Having offsite backup like Backblaze can help.

For more on best backup practices, make sure to check out Backblaze’s Backup Guide.

Have a question? Let us know in the comments. And if you have ideas for things you’d like to see featured in future installments of What’s the Diff?, please let us know!

Note: This post was updated from March 15, 2016. — Editor

Roderick Bauer

Roderick Bauer

Content Director at Backblaze

Roderick has held marketing, engineering, and product management positions with Adobe, Microsoft, Autodesk, and several startups. He's consulted to Apple, Microsoft, Hewlett-Packard, Stanford University, Dell, the Pentagon, and the White House. He was a Ford-Mozilla Fellow in Media and Democracy with Common Cause in Washington, D.C., where he advocated for a free, open, and accessible internet for all, reducing media consolidation, and transparency in politics and the media.

He is Content Director for Backblaze.

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