RAM Capacity and Cost

RAM has a much smaller capacity than secondary storage, and it costs more for each gigabyte it can hold. RAM is built from faster, more complex memory chips that are harder to manufacture, so fitting lots of it would make a computer very expensive. Secondary storage uses cheaper technology, so it can offer far more space for the same money.

RAM capacity is usually measured in gigabytes (GB), while larger secondary storage is often measured in terabytes (TB). A gaming PC advertised with 32 GB of RAM has 32 gigabytes of main memory; the same machine might come with a 4 TB hard disk, which is about 4000 GB of secondary storage.

For example, imagine 8 GB of RAM costs £40, which is £5 per GB. A 1 TB (1000 GB) hard disk costing £40 works out at 4p per GB. For the same £40, the hard disk holds 125 times as much data, even though each gigabyte of RAM is far more expensive to make.