What is ROM?

 ROM, or read-only memory, is a form of memory that a computer can read but not write onto. ROM is often used to store and play back music (CDs) or movies (DVDs). Unlike RAM, a computer can’t write new data onto ROM, it can only read it, or play it back.

How do I get more RAM without upgrading?

If you’re struggling with low PC performance, or if your computer has only 4GB of RAM or less, the best way to improve computing speed without buying a new machine is to free up your available RAM. There are two ways to get more RAM without upgrading your RAM cartridges:

Close active programs. Any browser tabs you have open (especially in Chrome) or applications you’re running consume RAM. So if you don’t need a tab open or aren’t actively using an app, close it. Only launch what you actually use.

Use Sleep Mode: Our own Avast Cleanup includes a feature that frees up memory by hibernating applications you don’t use. Get Avast Cleanup to free up RAM.

What should I look out for when buying RAM?

The latest generations of DDR4 RAM clock in at around 2,400MHz. Gamers will want DDR4 memory that operates at speeds of around 3,200MHz for Intel chips and 3,600MHz for AMD chips. Other users (such as professional programmers, multimedia editors, and hardcore gamers) may look for higher clocked memory with speeds up to 4,800MHz from specialist manufacturers like G.Skill or Corsair.

Clock speeds are one thing, but another important factor to consider when buying RAM is latency — the time delay between when a command in memory is entered and when it’s executed. The lower the latency, the higher the performance.

For high-level performance, you’ll need memory above 4,000MHz with a latency of around CAS (Column Address Strobe or Signal) 15-18 or less. When buying RAM, you might see this listed as CL 16 (Column Latency 16), for example. For regular users, this is unlikely to make a meaningful impact, but gamers should take note.

And if you want to upgrade RAM on your Mac, ensure it's possible to add RAM to your model before you start shopping.