Editing Non-volatile random-access memory (section)

==Commercialized Alternatives==

Flash and EEPROM's limited write-cycles are a serious problem for any real RAM-like role. In addition, the high power needed to write the cells is a problem in low-power roles, where NVRAM is often used. The power also needs time to be ''built up'' in a device known as a [[charge pump]], which makes writing dramatically slower than reading, often as much as 1,000 times. A number of new memory devices have been proposed to address these shortcomings.

===Ferroelectric RAM===

To date, the only such system to enter widespread production is [[ferroelectric RAM]], or F-RAM (sometimes referred to as FeRAM). F-RAM is a [[random-access memory]] similar in construction to [[DRAM]] but (instead of a [[dielectric]] layer like in DRAM) contains a thin ferroelectric film of [[lead zirconate titanate]] [{{chem2|Pb(Zr,Ti)O3}}], commonly referred to as PZT. The Zr/Ti atoms in the PZT change polarity in an electric field, thereby producing a binary switch. Unlike RAM devices, F-RAM retains its data memory when power is shut off or interrupted, due to the PZT crystal maintaining polarity.  Due to this crystal structure and how it is influenced, F-RAM offers distinct properties from other nonvolatile memory options, including extremely high endurance (exceeding 10<sup>16</sup> access cycles for 3.3&nbsp;V devices), ultra low power consumption (since F-RAM does not require a charge pump like other non-volatile memories), single-cycle write speeds, and gamma radiation tolerance.<ref>{{cite web|url=http://www.ramtron.com/about-us/what-is-f-ram.aspx |title=F-RAM Memory Technology  |website=Ramtron |access-date=2012-06-08 |archive-url=https://web.archive.org/web/20120418102351/http://www.ramtron.com/about-us/what-is-f-ram.aspx |archive-date=2012-04-18}}</ref> [[Ramtron International]] has developed, produced, and licensed [[ferroelectric RAM]] (F-RAM), and other companies that have licensed and produced F-RAM technology include [[Texas Instruments]], [[Rohm]], and [[Fujitsu]].

===Magnetoresistive RAM===

Another approach to see major development effort is [[magnetoresistive random-access memory]], or MRAM, which uses magnetic elements and in general operates in a fashion similar to core, at least for the first-generation technology. Only one MRAM chip has entered production to date: [[Freescale Semiconductor|Everspin Technologies]]' 4 Mbit part, which is a first-generation MRAM that utilizes cross-point field induced writing.<ref>{{cite web|url=http://www.everspin.com/technology.html|title=Technology|website=Everspin|archive-url=https://web.archive.org/web/20090610070935/http://www.everspin.com/technology.html|archive-date=June 10, 2009}}</ref> Two second-generation techniques are currently in development: [[Thermal Assisted Switching]] (TAS),<ref>{{cite web|title=The Emergence of Practical MRAM |first=Barry |last=Hoberman |website=Crocus Technology |url=http://www.crocus-technology.com/pdf/BH%20GSA%20Article.pdf |access-date=2009-07-20 |url-status=dead |archive-url=https://web.archive.org/web/20110427022729/http://www.crocus-technology.com/pdf/BH%20GSA%20Article.pdf |archive-date=2011-04-27}}</ref> which is being developed by [[Crocus Technology]], and [[spin-transfer torque]] (STT) on which Crocus, [[Hynix]], [[IBM]], and several other companies are working.<ref>{{cite web|url=https://www.eetimes.com/tower-invests-in-crocus-tips-mram-foundry-deal/ |title=Tower invests in Crocus, tips MRAM foundry deal |first=Mark |last=LaPedus |date=2009-06-18 |website=[[EE Times]] |access-date=2020-01-09}}</ref> STT-MRAM appears to allow for much higher densities than those of the first generation, but is lagging behind flash for the same reasons as FeRAM &ndash; enormous competitive pressures in the flash market.

===Phase-change RAM===

Another solid-state technology to see more than purely experimental development is [[Phase-change RAM]], or PRAM. PRAM is based on the same storage mechanism as writable [[CDs]] and [[DVD]]s, but reads them based on their changes in electrical resistance rather than changes in their optical properties. Considered a dark horse for some time, in 2006 [[Samsung]] announced the availability of a 512 Mbit part, considerably higher capacity than either MRAM or FeRAM. The areal density of these parts appears to be even higher than modern flash devices, the lower overall storage being due to the lack of multi-bit encoding. This announcement was followed by one from [[Intel]] and [[STMicroelectronics]], who demonstrated their own PRAM devices at the 2006 [[Intel Developer Forum]] in October.

[[Intel]] and [[Micron Technology]] had a joint venture to sell PRAM devices under the names [[3D XPoint]], Optane and QuantX, which was discontinued in July 2022.<ref>{{cite news |last1=Mann |first1=Tobias |title=Why Intel killed its Optane memory business |url=https://www.theregister.com/2022/07/29/intel_optane_memory_dead/ |access-date=2022-11-18 |work=The Register |publisher=Situation Publishing |date=2022-07-29}}</ref><ref>{{cite web |url=https://pcper.com/2017/06/how-3d-xpoint-phase-change-memory-works/ | title=HOW 3D XPOINT PHASE-CHANGE MEMORY WORKS | date=June 2, 2017 |author=Allyn Malventano | website=PC Perspective}}</ref>

[[STMicroelectronics]] manufactures phase-change memory devices for automotive applications.