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  1. #1
    New Member
    Join Date
    Dec 2012

    FSB:DRAM ratio question

    I was reading up on FSB: DRAM ratio. I looked at mine on CPU-Z, and it doesn't make sense to me. I found equations to calculate the ratio online, and none of the math seems to match up for me. Can someone tell me if these settings make sense to them? If so, can you explain how with the settings provided, the ratio comes out to be 1:5?

    p.s. My multiplier fluctuates from 36 to 38, DRAM frequency remains constant...





  2. #2
    5up3r m0d3r4t0r
    Overclockers.com Editor

    MattNo5ss's Avatar
    Join Date
    Aug 2008
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    AL
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    FSB:RAM ratios don't really matter on the newer chipsets since the FSB (or bclk) usually remains constant, and OCing is done via CPU multipliers and RAM multipliers with the base clock staying at ~100MHz.

    Back in LGA775, OCing had to be done by increasing FSB since CPU multipliers were locked. So, the FSB:RAM ratio was important because as you increased the FSB the RAM speed would increase at the same time and you wanted to get the highest FSB as possible without the RAM being a limiting factor. Typically, 1:1 ratios were used while OCing the CPU to give the FSB more room to increase before it reached the point where the RAM would be running higher than spec.

    Your current FSB:RAM ratio would be 1:6.667 since 99.78/99.78 = 1 and 665.3/99.78 = 6.667.
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  3. #3
    New Member
    Join Date
    Dec 2012
    Thank you, that's the ratio I was getting as well. I was just confused as to why CPU-Z gave me an incorrect ratio :/

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