Graphics card memory question

By HPCE_Larry
Feb 7, 2007
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  1. Some cards have the speed with (effective) after it and others don't. What does that mean? What would be faster, 1450 or 1450(effective)?

    As a seperate question, would a gfx card with really fast clock speeds but 256mb of ram do better than a card with 100mhz less in clockspeeds but a full 512mb ram?
  2. kitty500cat

    kitty500cat Newcomer, in training Posts: 2,407   +6

    Why is DDR RAM called DDR? DDR stands for double data rate (meaning that they can get 2 bits of data per pin in 1 clock cycle, as opposed to 1 bit in single data rate). DDR400 actually runs at 200MHz, but the double data rate essentially doubles the speed. So while it's only running at 200MHz, it's essentially 400.

    So if the RAM on a graphics card is running at 1450MHz effective, its actual clockrate is probably 725MHz, just running at double data rate.
  3. HPCE_Larry

    HPCE_Larry Newcomer, in training Topic Starter Posts: 189

    so 1450 would by faster than 1450(effective)?
  4. kitty500cat

    kitty500cat Newcomer, in training Posts: 2,407   +6

    Probably not. When they refer to 1450, they're talking about an actual 725, effective 1450. In other words, I don't think that their saying "effective" makes any difference to what they mean.
  5. agi_shi

    agi_shi Newcomer, in training Posts: 507

    Technically, yes. But if you're looking on newegg (or some other place) it's probable that they mean 1450 effective, just didn't write it. I haven't seen a card run its memory at 2900MHz :eek:

    And yes, a card with faster clocks but half the VRAM will be faster than a slower card with more VRAM. All that video ram does is store textures (I believe), so more VRAM simply lets you store more textures (or higher quality ones) - that is, it doesn't have anything to do with speed.
  6. cfitzarl

    cfitzarl TechSpot Chancellor Posts: 2,520   +9

    I dream to see that day :D !
  7. wolfram

    wolfram TechSpot Paladin Posts: 2,605   +9

    It should be GDDR5 RAM lol :)
  8. tweakboy

    tweakboy TechSpot Maniac Posts: 518

    Theres no difference, its the same!
  9. ZaUcY

    ZaUcY Newcomer, in training Posts: 89

    GDDR5 ram

    i just ordered a 4870 and have been looking at the specs on these cards..... how come on all the cards with GDDR5 ram calculate their speed by the memory clock x4?! i mean its still "double data rate" ram so i thought it should only be multiplied by 2.
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