This Week, in Memory

As spice modeling for memristive circuits matures and begins to show the possible scope of theoretical applications, and Apple pushes towards SSD adoption, and Sandisk flash memory conquers investor outlooks, and memcapacitance mutators are successfully modeled, and flexible graphene oxides move towards experimental reram fabrication, and spin computing gets its own graphene boost, it may be worth while to avoid the human Von Neumann bottleneck of too much, too fast, with not enough bus width by stepping through, in linear fashion, and in a little more depth, some of this weeks advances in the memory field:

1. First off, take a look at the new partnership between the Sharp Corporation and Elpida Memory Inc. (of Japan), in which they are developing a ReRam memory chip they hope to bring to market and full commercialization by 2013:
   

   “The National Institute of Advanced Industrial Science and Technology, the University of Tokyo and other chip equipment makers will join Elpida and Sharp Corp, the world’s No. 3 maker of solar cells, in this effort.” [ Reuters UK ]

2. This is right on the heels of SanDisk outperforming investors expectations, in large part because of tablets and mobile flash:
   

   “SanDisk Corp beat profit and margin expectations by reining in costs and keeping prices stable, and foresees a 2011 surge in demand as more consumers opt for smartphones and tablets.” [ NYT / Reuters US ]

3. Of course, SanDisk has an even larger boost from the fact that its a big NAND supplier, and Apple, who announced this week they were going to champion Flash and SSD’s going forward as their storage medium of choice, even with its flaws, hyped up their new Apple MacBook Air 11 inch, where the Solid State Disk [SSD] is the default, and the standard HDD is the “option”:

   Kasper Jade, citing a “person with a proven track record of pinpoint accuracy,” writes on the AppleInsider Web site that the new MacBook Air will be completely redesigned and will come with a new type of hard-drive called an “SSD Card” that looks more like a “stick of RAM, yet is not easily user-replaceable.” [ NYT Bits ]

   This is a great move forward. Since the early netbook days when the Asus eeepc first shipped all its models with the 16gb/20gb SSD in 2008, (windows smaller, linux option larger ssd), everyone jumped off the netbook SSD option. Its good to see its coming back, proprietary and soldered as it may be:

   “Most components — RAM included — are soldered to the logic board, preventing them from being replaced. […] The one standout in this proprietary sea is the 64 GB SSD. It’s not locked down like the rest of the components, although it is a very slim and unusual form factor (for a hard drive). It’s attached to the logic board with what appears to be a new mini-SATA (mSATA) connector..” [ ifixit, via ZDNET ]

4. Seagate reps, though, fought back against Apples SSD evangelicism with its own view of the storage battles:
   

   “I can tell you that my SSD drive takes about 25, 30 seconds to boot now versus the 12 seconds when I bought it,” Luczo said. “And that’s just an issue more related to OS than it is specifically to the technology but again with the hybrid there is things that you can do it alleviate that so your boot times are actually as compelling one and two, three and four years down the road.” But will SSDs replace traditional hard drives? Not surprisingly, Luczo said they would not. [ PC Mag ]

5. If only all these competing interest could be a little more flexible… perhaps advances in using thin graphene oxide films to produce flexible versions of memristors and other nonvolatile and ReRam type memory applications could help out:
   

   “However, although the metal oxide based resistive memories have several advantages, such as good scalability, low-power consumption, and fast switching speed, their application to large-area flexible substrates has been limited due to their material characteristics and necessity of a high-temperature fabrication process. As a promising nonvolatile memory technology for large-area flexible applications, we present a graphene oxide based memory that can be easily fabricated using a room temperature spin-casting method on flexible substrates and has reliable memory performance in terms of retention and endurance.” [ Nano Letters ]

6. And if all that wasnt enough, memcapacitance is getting a boost, at least in some spice models, as Czech researchers model a mutator for testing memristance relations to memcapacitors:
   

   “A recently published circuit that operates as a memcapacitor (MC), utilising a memristor (MR) emulator, is analysed with a confirmation that it simulates MC only approximately. A MR to MC mutator is designed by means of off-the-shelf circuits. The SPICE analysis confirms that this circuit transforms exactly the constitutive relation of MR into the constitutive relation of MC.” – [ Electron Letters (IET) ]

7. And last but not least, and certainly not last, the logic/memory hybrid NUMA advances: (not numa numa numa). Physicists at UC Riverside took a step closer to developing a spin computer [aka along the lines of earlier transputer or processor in memory models] utilizing tunneling spin injection (again, via graphene substrates, unlike other spintronic memristors), bringing hybrid IC chips combining logic with nonvolatile memory closer to fab:
   

   “[The] team has been able to lengthen the spin lifetime through the use of a nanometer-thick insulating layer, known as a “tunnel barrier,” in between the ferromagnetic electrode and the graphene layer. They found that the spin injection efficiency increased dramatically…” [ computerworld ]