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    Why 667MHz ram?

    Discussion in 'Hardware Components and Aftermarket Upgrades' started by Kyrre, Dec 10, 2007.

  1. Kyrre

    Kyrre Notebook Enthusiast

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    Hey guys, something has been puzzling me recently as i'm about to buy 4gb of ram for my laptop. (Vista..)
    I'm not really the type for overclocking so i've not come across this before.


    Most of the mobile core 2 duo chips, or mine in particular (T7250, 200MHz x 10 = 2GHz) have a 200MHz frequency.
    Wouldn't this mean that the best memory it could make use of would be 400? You'd need to overclock that core to 333x10 = 3.3GHz to match 667 memory at 1:1 sync.


    Am I missing something? Fill me in please.
     
    Kyrre, Dec 10, 2007
    #1
  2. Rene S - Zepto

    Rene S - Zepto Company Representative

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    The Santa Rosa laptops only run 800MHz FSB between the CPU and chipset. The speed between the chipset and RAM are still only 667MHz (PC5300), so you would gain nothing by getting 800MHz RAM (PC6400), only draining your bank account :)
     
    Rene S - Zepto, Dec 10, 2007
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  3. adinu

    adinu I pwn teh n00bs.

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    Yeah as he said, your chipset will not support 800MHz ram. So no matter what ram you get, whether it is pc5300 or 6200, it will only run at 667MHz.
     
    adinu, Dec 10, 2007
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  4. Kyrre

    Kyrre Notebook Enthusiast

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    How do you know the speed between my chipset and ram is 667?

    I thought ram speed = cpu frequency x 2?
     
    Kyrre, Dec 10, 2007
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  5. sly

    sly m1530 owner!!!

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    ram comes in 533 667 and 800mhz i think. but only desktop processors can use the 800mhz effectively
     
    sly, Dec 10, 2007
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  6. adinu

    adinu I pwn teh n00bs.

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    Because your ram is running at the speed of 667MHz.
     
    adinu, Dec 10, 2007
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  7. MegaBUD

    MegaBUD Notebook Evangelist

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    Well i you find cheaper 800mhz ram buy them but they will be downclock to 667 in your computer anyway

    ram is cheap now... i just bought 2x2gig 667 corsair for 2x45$can
     
    MegaBUD, Dec 10, 2007
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  8. Soulburner

    Soulburner Notebook Evangelist

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    If we could change the divider this wouldn't be a problem.

    All we need is 1:2.
     
    Soulburner, Dec 10, 2007
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  9. Kyrre

    Kyrre Notebook Enthusiast

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    Thanks for the comments, i'm starting to understand now [:
     
    Kyrre, Dec 10, 2007
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  10. deputy963

    deputy963 Notebook Evangelist

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    Why 667MHz ram? Because 666MHz is Evil! :)

    Sorry, I couldn't resist!
     
    deputy963, Dec 12, 2007
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  11. ekwipt

    ekwipt Notebook Enthusiast

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    Are you able to change the rams latency timings with out affecting mhz?

    For example most Laptop ram runs at 667mhz and CL5 where as 533 runs at CL4.

    Are you able to get quality ram running at 667mhz CL4?

    What if your bios doesn't take overclocks what programs can you use?
     
    ekwipt, Dec 24, 2007
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  12. Tony_A

    Tony_A Notebook Evangelist

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    CAS4 PC2-5300 RAM currently maxes out in 1GB sticks---no low latency 2GB sticks yet, just CAS5 ones....

    That said, it's a simple drop-in replacement to use the lower latency RAM. No "overclocking" required---(on the laptops I've upgraded at least....). Just make sure all your RAM is CAS 4---don't mix the speeds or you'll run at the slowest setting.
     
    Tony_A, Dec 24, 2007
    #12
  13. Soulburner

    Soulburner Notebook Evangelist

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    Of course you can - there is CL4 DDR2 running up to 800mhz and higher. It just takes more voltage, which is not adjustable on these laptops.
     
    Soulburner, Dec 24, 2007
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  14. ekwipt

    ekwipt Notebook Enthusiast

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    ekwipt, Dec 24, 2007
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  15. Soulburner

    Soulburner Notebook Evangelist

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    You can change RAM timings in Windows, but only on Nvidia chipsets. So, no you cannot change them unless you are in the BIOS of an Intel board. Since laptops don't have those kinds of options, you are stuck with SPD timings.

    G.Skill is good stuff.
     
    Soulburner, Dec 24, 2007
    #15
  16. powerpack

    powerpack Notebook Prophet

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    The OP unless I am missing something is confusing Cpu Clock with FSB, two different things. CPU speed has nothing to do with the RAM speed. It is FSB or memory bus. On yours even though FSB is 800Mhz memory bus is 667 my AMD has a 800Mhz memory bus "HyperTransport".
     
    powerpack, Dec 24, 2007
    #16
  17. Vizel

    Vizel Notebook Consultant

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    Ooh, just to mention

    AMD notebook platform does support PC-6400 Ram (DDR2 800Mhz) unlike santa rosa
     
    Vizel, Dec 25, 2007
    #17