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An Overview of Quad Band Memory

Posted by chrisd on from the via-and-intel-ain't-pals dept.

tedgyz writes "AnandTech has a short article on a new memory technology from Via, called Quad Band Memory (QBM). Rather than using dual-channel DDR to increase bandwidth, they use phase-shifting inside the memory modules to accomplish the same goal. The end result is simpler (and presumably cheaper) motherboard designs that are backwards compatible with current DDR modules. The downside? It is currently only going to available in a P4 chipset that Intel has not authorized."

10 of 125 comments (clear)

  1. wow, interesing by diablo6683 · · Score: 1, Interesting

    hmm, i wonder what the commercial applications of this are :)

  2. It's Kentron's invention by HardCase · · Score: 5, Interesting
    You can see more about this on Kentron's web site. They developed the technology, then released it, royalty free, to manufacturers.


    Given the memory manufacturers' resistance to DDR400 and the achingly slow progress that DDR2 is taking (the module standard isn't even final yet), this technology has a pretty good potential to reach production.


    -h-

  3. The real quesiton is..... by mrjive · · Score: 2, Interesting

    ...how long will it take for the major chipset makers (Via, SiS) to adopt this technology? It'd be great to see this available on the Athlon platform in the near future.

    --
    If you can't beat them, arrange to have them beaten. -George Carlin
    1. Re:The real quesiton is..... by xWeston · · Score: 2, Interesting

      Athlons arent currently sufferring from lack of memory bandwidth, but instead they have some other bottlenecks. P4's on the other hand are not fed the memory bandiwdth they need with DDR ram which is why they run faster with RDRAM. Technology like this will hopefully help the future AMD processors but the athlons seem limited by other factors

  4. I dunno, these are gonna cost more. by io333 · · Score: 4, Interesting

    From the article:

    *snip*

    Here's where the difference between QBM and conventional modules comes into play; QBM modules will have a set of 8 registers (QBM-10) as well as a phase-locked loop (PLL). The purpose of the PLL is to take the incoming clock signal from the chipset and shift it by 90 degrees; this shifted signal is then fed to the second bank of the DIMM, while the first bank receives the unaltered clock directly from the chipset.

    The 8 registers then switch between which bank gets to transfer data every clock; because of the 90 degree phase shift, there is a slight delay in transferring data from the second bank but both transfers actually end up happening within a single clock cycle. The end result is that you get two DDR transfers per clock, or 4 bits of data are sampled per clock thus doubling the throughput of DDR (hence the name Quad Band Memory).

    *snip*

    QBM modules will obviously be more expensive than regular DDR modules, the question of how much remains to be answered however.

    Let's see, one PLL... damn, I don't know if I can afford the extra six cents!

    (That extra six cents though doesn't detract from fact that this idea is just pure genius... with about 30,000 folks slapping their forheads for not thinking of it first!)

  5. If it's *that* simple... by Galahad2 · · Score: 2, Interesting

    If it's *that* simple to double the data rate of memory, why don't they, for example, divide the memory architecture into eight sectors and have each bit of a byte on a different sector, making 16x memory? It seems that this philosophy has no limit, as long as you have lots of sectors. What's preventing people from doing that?

    Sorta like a beowulf cluster of chips, really :).

  6. Re:I always love... by Gizzmonic · · Score: 2, Interesting
    I couldn't agree more. Anandtech, Tom's Hardware Guide, etc are basically circle-jerks for "l33t" Windows gamers who want to justify their unfortunate tendency to drop big bucks on the "latest and greatest" computer hardware.

    "Technical articles" basically consist of, "okay, here's this new chipset, let's compare it to an older chipset, (CLICK TO THE NEXT PAGE TO SEE MORE BANNER ADS). Wow, the new chipset (which just happens to be made by one of our advertisers) performs faster than the old one, as evidenced by this graph where the red line is 1/10 of an inch longer than the blue line."

    I quit reading that tripe years ago-the incestuous relationships between those sites and their advertisers is even worse than AOL ads on TNT. Please, don't click through on this article and give these fuckers more undeserved money.

    --
    (-1, Raw and Uncut is the only way to read)
  7. why is that a downside? by geekd · · Score: 5, Interesting

    The downside? It is currently only going to available in a P4 chipset that Intel has not authorized."

    Why is this a downside? Why should I give a rat's ass what Intel "authorizes".

    Intel sure as hell didn't authorize my Athlon on it's Abit mobo with a Via chipset.

    Is there an actual downside to not getting Intel's blessing (downside for consumers, not the company making the mobo)?

  8. Terrestrial cosmic ray intensities by richard-parker · · Score: 5, Interesting

    Radiation(white noise) was always a problem with RAM, much more so at higher elevations(Colorado gets about 100x more ram errors than sealevel does, necessitating ECC ram)
    Actually, the increased RAM failure rate due to the greater cosmic ray intensities at higher altitudes isn't as bad as you describe.

    For example, the expected soft-fail rate of a computer memory system in Denver, Colorado is about 4 times greater than the rate expected at a city it sea level (such as New York City). Even in Leadville, Colorado (which is located at 10,151 feet) the expected failure rate is only about 13 times greater than in NYC. No location in Colorado even approaches 100x.

    For more information, see the following paper:
    J. F. Ziegler, "Terrestrial cosmic ray intensities", IBM Journal of Research and Development, Vol. 42, No. 1, 1998.
    It can be found online here.
    1. Re:Terrestrial cosmic ray intensities by richard-parker · · Score: 2, Interesting

      One would think that with all that LEAD lying all over the place, cosmic ray showers wouldn't be such an issue...
      While I am sure you meant your comment to be facetious, I felt it deserved a reply due to the assumption that underlies it.

      When a cosmic ray hits the atmosphere it produces many secondary particles, it is these particles which cause soft errors in computer memory. For computer memory the worst secondary cosmic rays are the hadrons (protons, neutrons and pions). Neutrons are particularly troublesome since these are responsible for more than half of the terrestrial soft errors. In order to affect the computer memory these neutrons have already had to pass through kilometers of atmosphere, through the building, and through the computer housing - a little lead isn't likely to stop them. In fact, surrounding your computer with lead could even make things worse. Cosmic rays are often counted with a neutron monitor and it is not uncommon for neutron monitors to be deliberately constructed with a lead casing. The lead casing increases the neutron count by producing more neutrons as it is bombarded by cosmic rays.