Talk:Magnetoresistive random-access memory
|WikiProject Electronics||(Rated C-class)|
|WikiProject Computing / Hardware||(Rated C-class)|
- 1 "fab"
- 2 "faster than SRAM"
- 3 needs expansion of info
- 4 history?
- 5 Core memory
- 6 Just found an article interesting regarding the history of MRAM
- 7 MRAM vs DRAM
- 8 External magnetic field
- 9 MRAM has nothing to do with memristors
- 10 Requested move
- 11 language needs to be time-independent
- 12 MRAM v/s ReRam
Reading the section "Comparison with other systems: Overall" was weird because of the use of the word "fab" as an abbreviation for "semiconductor fabrication plant." I'm guessing that "fab" is an industry slang word and that the person who wrote the passage is from the industry, but... my first thought when reading the word was "fabulous," not "fabrication plant." So, for others who are not in the fabrication industry, the word choice should be less casual and more encyclopedic. If not that, then at least define "fab" in the article and gradually increase the frequency of its use so newcomers aren't distracted by it. --Humanist Geek (talk) 04:10, 23 May 2010 (UTC)
"faster than SRAM"
Is it really supposed to be faster than the SRAM used for CPU caches? The main part of the article only mentions that it should be denser than SRAM. Amaurea 17:43, 19 December 2005 (UTC)
Hmm, could do with scientific references here to justify these statements. A quick google gives me an article from this April in Science , which says "IBM has obtained read times of 3ns in 1kb research memories, Freescale has demonstrated a 25-ns cycle time for its 4-Mb MRAM, and Cypress Semiconductor is targeting a 70-ns cycle time for its 256-kb MRAM." The article in Science states that there is recent research which indicates that much faster MRAM may be produced in future. So I think it depends on whether you're talking about the situation right now (I think 10ns cycle time SRAM is available currently), or what the potential of the technology is.
- Freescale Semiconductor data sheet for MR2A16A, see www.freescale.com and enter Part Number MR2A16A.
- Cypress Semiconductor datasheet for CY9C62256, see www.chipcatalog.com/Cypress/CY9C62256-70SC.htm.
Average Earthman 18:49, 19 December 2005 (UTC)
i beleive the "faster than SRAM" was a misquote by wired.com from IBM, who quoted it as being 6x faster than DRAM.. (corrected)
was this page taken from www.mrsci.com/Computer-Memory/MRAM.php , or did they steal it from wikipedia?? - 2nd feb —The preceding unsigned comment was added by 184.108.40.206 (talk • contribs) 20:26, 5 February 2006 (UTC)
- They copied it from Wikipedia. Note that Wikipedia is not copyrighted. Average Earthman 20:45, 5 February 2006 (UTC)
- Well, it is under the GFDL, so they should give credit to Wikipedia and mention the license, ideally. I know some people here feel quite strongly about that (I don't though), and we have a page for listing noncompliant sites. mrsci does not seem compliant, and actually claims all rights for itself. Amaurea 10:02, 7 February 2006 (UTC)
needs expansion of info
Note: the description section needs to be expanded to include all the various types of MRAM. The comparison section needs to add other forms of memory such as FRAM. Earthsound 22:30, 3 January 2006 (UTC)
so..what happened between 1989 and 2000?
I'm pretty sure that Gary Prinz of the Naval Research Lab actually wrote the patent for MRAM in the 90s. The article reads like it is written by someonefrom IBM...pretty typical to leave off the accomplishments of others.
Sounds like MRAM is a much-refined reincarnation of the old core memory used back in 1401 and 1620 days. Jm546 00:12, 27 July 2006 (UTC)
- No more so than a hard drive – that's magnetic too. Note that MRAM, unlike core, has a non-destructive read. This leads to overall operation considerably different than core. On the other hand, FeRAM uses ferromagnetic elements, but does operate like core. There's no simple comparison here. Maury 22:09, 27 July 2006 (UTC)
Just found an article interesting regarding the history of MRAM
which recognizes "Northern Lights Semiconductor Corporation (NLSC)" for excellence research in MRAM. I heard NLSC has successufully developped 64Kbits MRAM since long time ago...say 2000..and demo that in many places. Now they have 1M&16Mbits design. Any one knows about this company? —The preceding unsigned comment was added by 220.127.116.11 (talk) 16:18, 31 January 2007 (UTC).
MRAM vs DRAM
The article seems to cover the issue of DRAM vs MRAM a lot. But realisticly, is MRAM really aiming to compete with DRAM? It seems to me that being non-volatile, it's more aiming to compete against other non volatile memory chips like PRAM, FeRAM and flash memory (NOR and NAND). Perhaps I'm wrong but it seems more likely that some other volatile memory chip will replace DRAM. Also, why is there no coverage of MRAM vs PRAM & FeRAM. As one of the AFAIK more promising NV rams in development seems to be it's more significant then MRAM vs DRAM. Also does it strike anyone else that parta are too duplicative. E.g. "Since the capacitors used in DRAM lose their charge over time, memory assemblies using them must periodically refresh all the cells in their chips approximately 1000 times a second, reading each one and re-writing its contents. This demands a constant power supply, which is why DRAM loses its memory when power is turned off on the computer." isn't this just telling us what volatile memory is? Wouldn't it be better to just say MRAM is NV and DRAM is V? Nil Einne (talk) 19:05, 8 December 2007 (UTC)
External magnetic field
What about resistance of MRAM to external magnetic field? Do the MRAM chips need protection from such fields, similar to floppy disks or hard drives? I think the article should contain some info about this. Ghalas (talk) 09:00, 10 June 2008 (UTC)
No. The shape antisotropy of these devices is so high that no magnet that the average person would have is capable of switching these devices. The magnetic field generated by a wire fall off by 1/r^2, therefore the only reason that they can be switched using external fields is because the fields are generated very close to the free layer. —Preceding unsigned comment added by 18.104.22.168 (talk) 04:21, 16 May 2009 (UTC)
I have a bachelor's thesis from my university which did actual measurements of MRAM resistance to external magnetic field and it showed that at 22mT MRAM start to generate errors, so a typical Neodymium magnet should be able to alter memory inside MRAM. The actual chip that was tested is MR2A16A. The research was done in 2009, so things might have changed, however I doubt that. Contact me if you need more info giedrius.medzevicius et gmail dot com. — Preceding unsigned comment added by 22.214.171.124 (talk) 10:21, 18 May 2013 (UTC)
MRAM has nothing to do with memristors
An editor recently added a line about this to the lead based on . If you click the link to the original EEtimes article this claim is not in there at all. I have no clue what's going on here with the Guardian, but this just doesn't make any sense. a13ean (talk) 15:18, 15 December 2011 (UTC)
Hi, first timer here :) it seems like the only person who claims MRAMs are memristors is Stan Williams from HP here, and the article he cited does not mention anything about MRAMs. Both devices perform different functions and putting these two very different devices together is at best confusing. L02T (talk) 07:58, 30 October 2012 (UTC)
language needs to be time-independent
MRAM is physically similar to DRAM in makeup, although often does not require a transistor for the write operation. However, as mentioned above, the most basic MRAM cell suffers from the half-select problem, which limits cell sizes to around 180 nm or more. Toggle-mode MRAM offers a much smaller size before this becomes a problem, apparently around 90 nm, the same size as most current DRAM products. To be worth putting into wide production, however, it is generally believed that MRAM will have to move to the 65 nm size of the most advanced memory devices, which will require the use of STT.
This was a good write up in 2006, but the data is now far from current. I suggest improving the page by specifying the year involved when claims about what is "current" are being made. Such as this rewrite for that particular paragraph:
MRAM is physically similar to DRAM in makeup, although often does not require a transistor for the write operation. However, as mentioned above, the most basic MRAM cell suffers from the half-select problem, which limits cell sizes to around 180 nm or more. Toggle-mode MRAM offers a much smaller size before this becomes a problem, which in 2006 was expected to be around 90 nm, the same size as most contemporary DRAM products. To allow for future growth however, it was generally believed that MRAM would have to move to 65 nm, the size of the most advanced memory devices at the time, and perhaps therefore requiring the use of STT.
This is pertinent because there are now SSDs coming to market with MRAM caches. I'm not sure if they are the STT variety. With DRAM and NAND now in the 20nm node, ahead of even intel IB processors, they obviously have pushed past 65nm with MRAM to be in the process of incorporating it in products.