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Samsung develops DDR4 memory, up to 40% more efficient

By Emil ยท 33 replies
Jan 4, 2011
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  1. captaincranky

    captaincranky TechSpot Addict Posts: 12,512   +2,305

    In fairness, this has very little truth in it. The best buys right now, are in DDR-3. It doesn't really make sense to compare pricing on the proverbial, "(DDR-4) bird in the bush", as it were.

    Supply and demand will work its magic, when in fact, DDR-4 is actually introduced. And for those special few that simply have to be the first kid on their block to have it, then you will have to pay a hefty premium for that privelege. (Oh, and those "select few" will be doing the same bellyaching that they were at the first release price of DDR-3).

    When DDR-3 becomes a "replacement part", then the price will go up. This is evidenced by that fact that both DDR, and DDR-2, are now selling at a rate of 150% of DDR-3, and DDR-3 isn't anywhere near EOL at present.
  2. Burty117

    Burty117 TechSpot Chancellor Posts: 3,041   +793

    I feel slightly sorry for Benny26. No one took it as sarcasm, I did because he put "I mean," and after that point in the post it becomes a bit more obvious.

    Anyway I guess this is a good thing for Laptop and Netbook owners, Although as DBZ mentioned we won't actually see this until around the time Intel enter the 16nm zone.

    Out of question incase anyone knows, what is different between GDDR and DDR types of RAM?
    As in is the underlying way the RAM works is totally different or is it smaller differences?
  3. dividebyzero

    dividebyzero trainee n00b Posts: 4,891   +1,262

    Jeez, you know how to ask the sticky questions!:D

    Okay here goes...
    All desktop (say DDR3) memory is based on a 64-bit memory bus* (so dual channel = 2 x 64 =128-bit, triple channel = 3 x 64 = 192-bit), GDDR as you probably know generally operates on a considerably wider bus because it utlises (typically) 4 or more channels ( 64 x 4 = 256-bit, 64 x 6 = 384-bit, 64 x 8 = 512-bit) - this allows for a much higher transfer rate (memory bandwidth), which leads to....

    ....main difference between desktop RAM and GDDR5 in particular, is that DDR uses a single write clock (transferring data at the both the highest and lowest point of each clock cycle-hence Double Data Rate) per cycle whereas GDDR5 uses two write clocks per cycle (enabling one data request+one data receive per clock cycle)- this translates as GDDR5 having twice the effective memory bandwidth that DDR.

    As example:
    Desktop RAM frequency =800MHz x 2 (Double Data Rate -DDR)= DDR3-1600
    GDDR5 = 1375MHz (HD 6970 clock) x 4 (2 write clocks x DDR) = 5500MHz "effective"

    GDDR also operates at a much faster rate at a much lower voltage. Typical destop RAM operates between ~2.2v (DDR2) and a low of ~1.35v (LoVo DDR3) while GDDR5 operates at ~ 0.95-1.05v (again, typically). Latency in GDDR is also lower than it's desktop counterpart.

    * ECC memory uses a 72-bit bus. The "extra" 8-bit's provide the error correction facility.
  4. Zecias

    Zecias TS Booster Posts: 202

    srry its hard to read sarcasm >.>
  5. captaincranky

    captaincranky TechSpot Addict Posts: 12,512   +2,305

    May we present the new and improved post # 2...!
    In response to "Benny's", attempted (?), "sarcastic" post...... may we present post # 29...!
    Well, it's a tad late to bother or belabor, wouldn't you say? "I mean really", if you didn't get the joke on the first few passes, it's probably better to just go ahead and get ready for the next one. Or perhaps you were being "sarcastic" yourself?

    "You can lead a horse to water, but you can't make him laugh"...! (Now I'm being sarcastic, if you were wondering).

    I thought I would add this one paragraph from the Wiki page on "DDR2", by way of explaining the mechanism in which DDR2 has become referred to as, "quad pumped"

    "Like all SDRAM implementations, DDR2 stores memory in memory cells that are activated with the use of a clock signal to synchronize their operation with an external data bus. Like DDR before it, the DDR2 I/O buffer transfers data both on the rising and falling edges of the clock signal (a technique called "double pumping"). The key difference between DDR and DDR2 is that for DDR2 the memory cells are clocked at 1 quarter (rather than half) the rate of the bus. This requires a 4-bit-deep prefetch queue, but, without changing the memory cells themselves, DDR2 can effectively operate at twice the bus speed of DDR".
  6. dividebyzero

    dividebyzero trainee n00b Posts: 4,891   +1,262

    Thanks captain
    And just to confuse further; GDDR uses an 8-bit prefetch.

    I'm not too sure what kind of answer (or level of answer) Burty was expecting. Explaining in laymans/simple terms tends to raise more questions than it answers (hence my "Jeez, you know how to ask the sticky questions" comment), and a generic "it uses less voltage and runs faster" leaves out a lot of pertinent information.
  7. technology these day move like mathematics logarithm..
  8. Many of these comments are among the funniest things I've seen today, on a Friday too!

    (Demi Moore's Law ... hahaha!!!)

    Thank you very much, I needed this (tough day)...

    -- thanks,

  9. Burty117

    Burty117 TechSpot Chancellor Posts: 3,041   +793

    Thanks for clearing that up guys :)

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