Fab plants are now making superfast carbon nanotube memory(computerworld.com) |
Fab plants are now making superfast carbon nanotube memory(computerworld.com) |
This technology has been around for a while. Lockheed Martin built a 4MB NRAM back in 2008, and sent it up with a memory tester on a Space Shuttle flight in 2009.[2] That was done in conjunction with Nantero; they had an arrangement for government products. The technology is inherently rad-hard, so it's useful for space operations.
This technology has been two years from volume production since 2008.[3] It's not clear why it hasn't reached production yet. It clearly works. It may just cost too much.
[1] http://nantero.com/nantero-closes-30m-series-e-round-its-nex... [2] http://www.nsti.org/events/NNI/sld/pdf/65.pdf [3] http://spectrum.ieee.org/tech-talk/semiconductors/devices/na...
If you asked me what the write cycle limitation of the registers in my haswell chip was, I'd shrug and say effectively unlimited. Which isn't far off what they said.
I have a hard time believing the durability presented (especially with remarks on how it might as well be an infinite number) for a process that involves movement and contact points.
So, if it's been tested continually for 10 years, why are the fabrication technologies behind? This sounds like marketing for vapor ware with as much hype shoved between the specs.
Since the contact points are CNTs I would believe it. Only diamond has a stronger lattice binding those carbon atoms.
How many times have you written to the same cell on your SSD? Current NAND chips have a write cycle limitation of somewhere around 10^6. Apparently a Taiwanese firm got it to 10^9 in 2012, but I'm guessing that hasn't arrived in production yet. So they have raised the write cycle limit by somewhere between 1000 and 1,0000,000. If you're wearing out your SSD once a year (I'll assume you are using it for swap or something), they've increased it to 1000 yrs. That's pretty much the minimum. So "almost infinite" seems reasonable.
The fastest DDR3 is PC3-17000 which has a write speed of 17000MB/s peak. Or roughly 16GB/s. http://en.wikipedia.org/wiki/DDR3_SDRAM
Assuming that you re-write your entire RAM every second, that's 10^12 seconds or about 32000 years. https://www.google.com/search?q=10%5E12%20seconds&rct=j
But if you're writing to your RAM at a 10 microsecond interval (say you're doing something like a firewall or HFT) and you keep re-using the same few megs of RAM then instead of 32000 years it's more like 4 months.
So it's fantastic for "durable" storage, but definitely not as good as SRAM or DRAM in general. The lifetime of SRAM and DRAM are both going to be based on the lifetime of the silicon which is roughly related to the temperature of the chip and the thermal migration of dopants. Hotter means more energy for dopants to move, but generally measured in many years or decades.