Forgot your password?
typodupeerror
Hardware

DDR4 May Replace Mobile Memory For Less 145

Posted by Soulskill
from the not-dance-dance-revolution dept.
Lucas123 writes "The upcoming shift from Double Data Rate 3 (DDR3) RAM to its successor, DDR4, will herald a significant boost in both memory performance and capacity for data center hardware and consumer products alike. Because of the greater density, 2X performance and lower cost, the upcoming specification and products will for the first time mean DDR may be used in mobile devices instead of LPDDR. Today, mobile devices use low-power DDR (LPDDR) memory, the current iteration of which uses 1.2v of power. While the next generation of mobile memory, LPDDR3, will further reduce that power consumption (probably by 35% to 40%), it will also likely cost 40% more than DDR4 memory."
This discussion has been archived. No new comments can be posted.

DDR4 May Replace Mobile Memory For Less

Comments Filter:
  • by blueg3 (192743) on Tuesday May 15, 2012 @11:01PM (#40012849)

    In order for a spec to be useful, you need to be able to actually build the specified system. The reason they don't encompass things that they can't currently build in the specs is that they want the specs to be useful.

  • Re:1.2V of power? (Score:5, Informative)

    by AdamHaun (43173) on Tuesday May 15, 2012 @11:03PM (#40012859) Journal

    Nerds should know Ohms law.
    http://en.wikipedia.org/wiki/Ohm's_law [wikipedia.org]

    and that there is no difference between voltage and power.

    Voltage and power are related, but that doesn't mean they're the same. In fact, Ohm's Law says that they're not -- you still need information about the current (or resistance) to determine power dissipation.

    Transistor switching in digital circuits is very different from plain resistance. It's more like charging and discharging capacitors. Energy loss is proportional to voltage squared, at least for dynamic power. That's why lowering the voltage is the most important thing for power consumption.

  • Re:1.2V of power? (Score:5, Informative)

    by hawguy (1600213) on Tuesday May 15, 2012 @11:17PM (#40012919)

    Nerds should know Ohms law.
    http://en.wikipedia.org/wiki/Ohm's_law [wikipedia.org]

    and that there is no difference between voltage and power.

    I don't think you understand the site you linked to. P = I * V -- If power and Voltage are the same, why are they on different sides of the equation?

    While it's true that voltage is proportional to power *if* current remains the same, you can't make a blanket statement that a new technology that runs at a lower voltage necessarily uses less power. The old Pentium Pro CPU had a TDP of around 35W with a core voltage of 3.3V, but a new Core i7 can have a TDP of 125W with a core voltage less than 1.5V. Half the voltage, 5 times the power dissipation (and a whole lot more transistors to power)

    When dealing with semiconductors, it's likely that lower voltage means less power, but not guaranteed.

  • Re:1.2V of power? (Score:4, Informative)

    by Bengie (1121981) on Wednesday May 16, 2012 @12:07AM (#40013163)
    Power consumption for computer chips

    C=Capacitance
    F=Frequency
    V=Voltage
    P=Power

    P=VC^2F

    Capacitance is static, so there are only two variables, F and V. As you can tell, amperage doesn't even play into the equation.

    A chip may draw amperage, but that is just a function of C and F.
  • Re:Excellent (Score:4, Informative)

    by TheRaven64 (641858) on Wednesday May 16, 2012 @03:55AM (#40013981) Journal
    I've found it interesting how this has been repeated and justified in so many ways over the years. The first time I heard this quote was the mid '80s, and it was '64KB ought to be enough for anyone', not 640KB. Back then, it was apparently related to a hard-coded limit in Microsoft BASIC, which limited it to 8-bit computers. The alleged context was that this was Bill Gates' facetious reply when asked about this limit with regards to the new 16-bit microcomputers. As I recall, early versions of Microsoft BASIC on the IBM PC only supported 64KB, even though the machine could address ten times as much.
  • by Sycraft-fu (314770) on Wednesday May 16, 2012 @04:49AM (#40014167)

    You think all Intel has to do is say "Hey! We'd like to support DDR4," and it just happens?

    Not so much, actually. First off it has to actually, you know, be a real specification. The spec isn't final and released yet. They can't really start to use something that isn't final and subject to change.

    Once it is actually out comes the harder part. They have to redesign the memory controller, which is on the chip now, to accommodate it. DDR4 isn't "DDR3 but faster," it is a different spec that works differently. Big different is no more RAM channels with multi-sticks. It is a point-to-point memory interface. So that is going to require a different setup, particularly to support large numbers of memory sticks. Also along with that the motherboards will have to be redesigned to accommodate the new RAM. Again given the point-to-point nature, the wiring would be different even if all the connectors were the same (which they aren't).

    Then of course those new chips have to be fabbed, tested and made ready for sale, and those boards have to be rolled out. After all that, they still need memory. The memory manufacturers will have to retool their lines and get DDR4 chips and sticks produced in quantity to be sold.

    When all that is done, then DDR4 can hit the market and go in your computer (if you purchase a new board, and processor).

    So, maybe give it 6-12 months, rather than just bitching at Intel for not "giving a damn"? Just because you don't understand how something works, doesn't mean it is easy to do. Implementing a new RAM spec isn't something you just snap your fingers on, it isn't a tiny patch for software. It is a pretty major thing.

    You'll probably see it in systems next year. Intel's roadmap says it will be coming to Haswell-EX server chips first, I haven't seen what AMD's plans are.

  • Re:Excellent (Score:3, Informative)

    by Kergan (780543) on Wednesday May 16, 2012 @04:49AM (#40014173)

    The part that you're forgetting is that Gates never said it:

    http://en.wikiquote.org/wiki/Bill_Gates#Misattributed [wikiquote.org]

  • Re:Excellent (Score:4, Informative)

    by arth1 (260657) on Wednesday May 16, 2012 @06:43AM (#40014591) Homepage Journal

    That's why there is ECC.
    Why anybody runs without it is beyond me.

    In the case of HHC, which TFS mentions, likely because you need to both buy, fit and power the extra circuitry. Added development costs, production costs, size requirements and larger power drain is a hard sell.

    On a PC, the main reason is that Intel only supports it on Xeon CPUs. A secondary reason is consumerism, where people pick the cheapest system that has "comparable" specs, without understanding minute differences, or caring about longevity.

    For servers, can you even buy them without ECC? Every single IBM or Dell system I've purchased over the last few years always came with ECC RAM. But the mind boggles when some expensive RAID controllers come with non-ECC RAM!

This is a good time to punt work.

Working...