|This is the talk page for discussing improvements to the Memory types template.
|WikiProject Computing / Hardware||(Rated Template-class)|
Memristor not a memory
- Is it wise to remove it without a trace? The memristor page still includes this template. It's true that memristors themselves are just one of the four passive circuitry elements, but its very clear that the bulk of our interest in them is for applications as computer memory. Are we really going to wait for a brand name to include this in a list? This decision is trading ease of navigation for technical correctness. 2620:0:1019:10:28C9:975F:5DA6:4354 (talk) 17:51, 8 July 2016 (UTC)
- I removed this template from the memristor page because it is an electrical element. For example, DRAM consists of a capacitor and a transistor, and 4-transistor SRAM consists of 2 resistors and 4 transistors. As the same, ReRAM, such as Intel's 3D XPoint, consists of a memristor and a crossbar switch, I think. Cafeduke (talk) 06:13, 21 March 2018 (UTC)
- That's because "virtual memory" isn't an actual type of computer memory, it's a method of accessing it. A quick look at that article should clear up just what it is, but in case it seems a bit opaque... It basically 're-directs' a program's memory access, to make the program believe it's using a single, monolithic block of memory, while secretly, it is really being provided with memory fragmented across numerous RAM modules, and even potentially on hard/solid state drives. The program won't know the difference; hence it runs fine. This does have the downside of potentially slowing RAM access speeds, but has the upsides of eliminating any other downsides of fragmentation, making sure all memory can be used, and making sure a computer can multi-task without each program bumping into other program's memory. Nottheking (talk) 03:03, 20 March 2010 (UTC)
As the article for Flash Memory currently states, "It is a specific type of EEPROM..." Hence, I am editing the indentation of it in the box to reflect this. Nottheking (talk) 03:03, 20 March 2010 (UTC)
- Yes, it is. The cross sectional structure of NAND gate type flash memory is almost the same as modern EEPROM. I think flash memory, an alias of Flash ROM, is not a NVRAM, because it can not be erased nor re-programmed randomly per byte. To flash or re-program some region, dedicated command is required. I never use a word Flash RAM, but this word is an alias in Wikipedia. Refer to the following site.
I have altered the name of the Williams tube to the Williams-Kilburn tube for the reasoning given at: Why Williams-Kilburn Tube is a Better Name for the Williams Tube --TedColes (talk) 17:15, 15 March 2012 (UTC)
Optical disc drive
Optical disk drive is also not a memory type, but it is just an equipment such as programmer (hardware), tape recorder, and cassette deck. As for memory type, section structure should be probably as follows. But this change is too drastic for me to correct. Some technologies, such as LaserDisc, CD, and DVD might be based on the same technology.
- Magneto-optical disk (including; MiniDisc, and so-called MO )
- Compact disc (including; CD-R, CD-RW, etc.)
- DVD (including; DVD-R, DVD-RW, DVD-RAM, etc.)
- HD DVD
might be enough, because there are too many specifications. I found a Template:Optical disc authoring. But it includes optical disk media types itself, other than authoring tools. I think this template should be divided into "Tools/Equipments" and "Optical Media Types."
- While I agree with the categorization here it is more fitting to group all of optical disks together as one as they are just different implementations of the same technology. Also I don't think "5D" optical storage belongs there, it is but one of myriads of optical storage techs in the lab, that one just got some marketing attention. It is not a computer memory tech yet. IdentityCrisis (talk) 17:48, 17 August 2020 (UTC)
As for mechanical memories, my images are:
Mechanical (Not need to be listed up) → See phtos.
Historical computers, such as Digital Equipment Corporation's PDP-11, had mechanical switches for booting. Nowadays, these are replaced with EEPROM-based BIOS,
Cafeduke (talk) 04:38, 20 March 2018 (UTC)
- I found that the term "mechanical" refers to "mechanically addressable" in the article Non-volatile memory. Cafeduke (talk) 08:26, 21 March 2018 (UTC)
SONOS is also not a memory type, but it is just a cross sectional structure of MOSFET for "EEPROM" and "flash memory", realized in late 70's. Renesas Electronics uses MONOS (metal-oxide-nitride-oxide-semiconductor) structure for their flash memories embedded in microcontrollers. The MONOS cross sectional structure itself is introduced as a kind of EEPROM technology in 1983 . MONOS is originally disclosed as a structure for EEPROM. So, SONOS and MONOS are cross sectional structure for both "EEPROM" and "flash memory". Refere to the following web sites. Intel has another naming of cross sectional structure both for EEPROM and flash memories, such as FLOTOX and ETOX, like 3D Xpoint. Of course, these are not the name of memory types.
- Threshold-alterable Si-gate MOS devices | IEEE
- A low-voltage alterable EEPROM with metal—oxide-nitride—oxide—semiconductor (MONOS) structures | IEEE
- "Renesas Electronics Develops 90 nm One-Transistor MONOS Flash Memory Technology" | Business Wire
- Renesas bets on SG-MONOS for MCUs with over 100MB of embedded flash | eeNews Embedded
- Gutmann (2001) papaer: "Data Remanence in Semiconductor Devices" | USENIX
3D Xpoint is not a general terminology. It is a 3-dimensional structure of Intel and Micron Technology. In general, it is roughly categorized into ReRAM; Resistive random-access memory. Samsung Electronics seems to have another 3-dimensional structure. Refer to the following conference paper, especially PDF page 20.
- Rohnert Park (2015) "3D Monolithic Resitive RAM" | IEEE S3S Conference
- "Partnership Puts ReRAM in SSDs" | EE Times
- "Leader: Accelerating ReRAM-based main memory by leveraging access latency discrepancy in crossbar arrays" | IEEE
DRAM and SRAM
DRAM has another template "Template:DRAM." So, each DRAM types should not be listed on this "Template:Memory types." They should be added to Template:DRAM.
Unfortunately, Wikipedia dos not have template for each SRAM types, such as asynchronous SRAM, pipeline-burst SRAM, QDR SRAM, etc. I wonder "QDR SSRAM" may refer to QDR SRAM. Cafeduke (talk) 08:18, 21 March 2018 (UTC)
Cypress Semiconductor's nvSRAM is not a memory types but a product name, which integrates 6-transistor SRAM, SONOS-based non-volatile memory, real-time clock, etc. Refer to the following product page. SONOS itself is a very old technology for cross sectional structure of MOSFET. SONOS is realized in 1977 by Fairchild Camera and Instrument.
Early stage NVRAM
What/who defines early stage here? As of 2020, NVRAMs that are seeing market presence are: PCM (because of 3D Xpoint, Intel and Micron seem to maintain a no-comment on whether they are really PCM but it is generally accepted that there is PCM tech in there) and barely MRAM. The rest have yet to make a dent in the market. So perhaps update to have these two as NVRAM and the rest as early stage? I will make the change in a few weeks or someone can do that before me. Also unrelated but note that ReRAM is an umbrella term. IdentityCrisis (talk) 17:48, 17 August 2020 (UTC)
- Change made, also upon inspection of the history ReRAM was up there merely because at that time Xpoint was thought to be a ReRAM... so everything is good now. IdentityCrisis (talk) 00:58, 25 September 2020 (UTC)