Why primary storage is much more expensive than secondary storage?

[Clarke]

Hi friends,

I am wondering, why just a bunch of gigs in RAM cost much more than a bunch of gigs in secondary storages. is it about how the RAM works vs HDD,SSD,etc. works? or is it about the materials use to make those storages?

 

[Davidwatson]

HDPE Tarpaulins | Fire Retardant Tarpaulin

 

[Akshay_M]

RAM is expensive because it's a manufactured 'thing' with billions of cells that must operate at incredibly high frequencies and where, essentially, they all have to work right, or it doesn't work (or doesn't work reliably).

Hard drives are simply a coating of magnetic material on a very smooth platter (or platters) with some physical components and electronics around it. If the magnetic layer is defective, it can often be mapped around.

We could make similar comparisons of optical and tape media. In essence, they are much cheaper to manufacture than RAM.