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Rambus and DDR RAM writeup

jerkychew writes "Hannibal over at Ars Technica has written part 3 of his RAM guide,, this time focusing on the technical details of Rambus and DDR RAM. As always, a good (if compliacted)technical read. " If you're not scared of pin counts and parity, then this is a cool article.

4 of 51 comments (clear)

  1. DDR SDRAM? Not until the lawsuits clear ... by ascheuch · · Score: 3

    I think the biggest problem with DDR SDRAM is the lawsuits. According to this article: http://www.tech-report.com/news_reply.x/882,

    June 16: Toshiba signed agreements with Rambus, Inc to pay Rambus royalties on SDRAM and DDR RAM based products. This development has the potential to seriously shake up the memory market. Toshiba has just set a precedent, and basically sold out the rest of the world's memory manufacturers.

    Basically, Rambus is making Toshiba pay huge $$$ to make and market DDR SDRAM. In that article, it states that the royalty rate is even higher than RDRAM. (which we all know is way overpriced!)

    Later on in the month, The Register ran this article: http://www.theregister.co.uk/content/3/11576.html

    This one is by Hitachi which is counter suing Rambus stating they have an unfair monopoly on memory. Now I'm no lawyer, but reading these articles ... I get very angry at what Rambus is trying to do.

    Taken from the register piece:
    Hitachi admits that the '804 Patent was issued to Rambus on September 21, 1999, and is entitled "Synchronous Memory Device Having An Internal Register."

    There's more legal stuff in there ... but basically these lawsuits need to be cleared before companies will invest in mass production of these chips.

    :P

  2. Re:Sig11 RAM Guide by Mark+F.+Komarinski · · Score: 3

    My (quick) reading of the article indicated that RAMBUS does have a few problems:

    1) More parts (thus, higher cost)
    2) Only access 1/2 the banks of memory at a time.
    3) RAMBUS claiming patents for SDRAM production doesn't make their case any better as well.

    That being said, will RAMBUS (aside from the political issues) give better performance..say...5 years from now, when we all have 2Ghz machines running with an 800Mhz FSB motherboard? Some of what I've seen implies that the performance is really nasty right now, but in a few years when CPU and FSB speeds increase, it could pick up more performance.

    --
    -- Ever notice that fast-burning fuse looks exactly the same as slow-burning fuse? I didn't... (Edgar Montrose)
  3. Re:DDR SDRAM (addendum) by ackthpt · · Score: 3

    A follow up I found on The Register, so at least ALi and IWill are in the hunt, preview boards out early fall... sigh. Gonna be a long wait until Christmas, I guess.

    Maybe I should just tighten the belt and go for the 1040MHz Alpha (w/DDR, AGPx2)

    Vote Naked 2000

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    A feeling of having made the same mistake before: Deja Foobar
  4. Re:DDR SDRAM? Not until the lawsuits clear ... by ErMaC · · Score: 4

    Here's the dirt:

    Rambus is a member of the JEDEC, a committee of Semiconductor manufacturers which was created to help set standards for different types of chips. All the major manufacturers are JEDEC members, as well as other companies including Intel and Rambus.

    One of the agreements to joining the JEDEC is that you must disclose all patents, finalized and pending, to the committee and you may not withhold such information, or use information gained in the JEDEC forums to file your own patents.

    Rambus decided not to follow the agreement, and instead filed a patent during the SDRAM standard negotiations which would attempt to patent the exact implementation of SDRAM which was being written up. In the patent office, if your patent is not granted you can get extensions on it by modifying it. So what they did is continually string the patent along for several years, modifying it slightly so that as the SDRAM (and later DDR-SDRAM standard) was finalized, their patent looked exactly like what the standard was supposed to be.

    Now the patent finally went through (god bless those morons in the patent office), and since everyone has implemented their RAM according to the standard, Rambus is suing them all for patent infringement.

    However, there is very little chance they'll win. First, they violated the JEDEC agreement. Second, there is certainly prior art. Third, there was a decision back in '96 (I think) against Dell Computer when they patented something which was the result of "An Industry-wide Standardization effort" where the courts ruled that their patent was unenforceable. This is going to happen to Rambus, as well.

    As for Hitachi and Toshiba backing down and paying license agreements there are specific reasons.

    After the settlement, Hitachi sold their RAM division to NEC. They don't have to deal with the problem now, and since NEC is incorporating Hitachi's RAM infrastructure into their own, the licensing agreements probably mean jack now.

    Toshiba, on the other hand, manufactures the RD-DRAM which is used in the PlayStation 2. They're making enormous amounts of money from this, and if they didn't agree to pay more licensing fees to Rambus, Rambus might pull their RD-DRAM license, thus forcing Sony to find someone else to manufacture the RAM.

    Hope this has been informative...

    --
    "I want to get more into theory, because everything works in theory." -John Cash