Universal memory

This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. Find sources: "Universal memory" – news · newspapers · books · scholar · JSTOR (January 2017) (Learn how and when to remove this template message)

Universal memory refers to a

- a CPU with a 4×256 KB L2 cache, and a 6 MB L3 cache

- 16 GB DRAM

- 256 GB solid-state drive, and

- 1 TB hard disk drive

Researchers seek to replace these different memory types with one single type to reduce the cost and increase performance. For a memory technology to be considered a universal memory, it would need to have best characteristics of several memory technologies. It would need to:

- operate very quickly – like SRAM cache

- support a practically unlimited number of read/write cycles – like SRAM and DRAM

- retain data indefinitely without using power – like flash memory and hard disk drives, and

- be sufficiently large for common operating systems and application programs, yet affordable – like hard disk drives.

The last criterion is likely to be satisfied last, as economies of scale in manufacturing reduce cost. Many types of memory technologies have been explored with the goal of creating a practical universal memory. These include:

• low-voltage, non-volatile, compound-semiconductor memory (demonstrated) ^[3][4]
• magnetoresistive random-access memory (MRAM) (in development and production)
• bubble memory (1970-1980, obsolete)
• racetrack memory (currently experimental)
• ferroelectric random-access memory (FRAM) (in development and production)
• phase-change memory (PCM)
• programmable metallization cell (PMC)
• resistive random-access memory (
  RRAM
  )
• nano-RAM
• memristor-based memory^[5]

Since each memory has its limitations, none of these have yet reached the goals of universal memory.

References