Memory Frequency

I don't know how to calculate my ddr3 bandwidth and speed at all
but on cpuz i get the followings:
dram frequency 400mhz
and the timings are 7-5-5-16 by my OC
have no idea how can actually these 1600mhz 3x1gb get used by my e4500 at full speed without OC' CPU
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  1. EDITS - Oops! Little confused, but CPUz makes mistakes often. Yes, I indeed did overlook this is a 775 socket CPU. :ange:

    The Core 2 Duo E4500 has a FSB of 800 MHz, so the Memory Multiplier is 4; see chart.

    Your question, "1600mhz 3x1gb" - by default DDR will run at 1066 MHz.

    BCLK X 4 = FSB
    BCLK X Memory Multiplier = DRAM Rate

    FSB:
    1333 / 4 = 333
    1600 / 4 = 400

    RAM:
    667 / 2 = 333
    800 / 2 = 400
    1066/ 2 = 533

    Asynchronous to the FSB:
    1:1 = 333 MHz : 667 MHz
    4:5 = 333 MHz : 833 MHz
    2:3 = 333 MHz : 1,000 MHz
    5:8 = 333 MHz : 1,066 MHz

    B_CLK times four is your FSB (once again, Front System Bus); B_CLK times your memory multiplier is your DRAM rate; B_CLK times your CPU's multiplier is your CPU frequency.

    BIOS Changes:
    1. Memory Multiplier = 4 {Some BIOS calulate this and give a drop-down menu - {1600 Mhz}
    2. CAS Settings = 7-7-7-16
    3. {Verify Auto} or set DRAM Voltage per spec'd DDR {e.g. 1.65V}

    In any case unless your BIOS fully recognizes you exact Part-Number XMP DDR then don't use XMP; BSOD/Post Failure/Unstable system will result otherwise. Example, XMP {MOBO Certified Memory Support List} - http://www.gigabyte.us/products/product-page.aspx?pid=3449#memory%20support%20list
  2. jaquith said:

    Little confused, but CPUz makes mistakes often. Not really. You just need to understand what it is trying to tell you. :)

    DRAM Frequency of 400 MHz is generally 800 MHz DDR2 speed {Double Data Rate}. or 1600 MHz DDR3 speed.

    Your question, "1600mhz 3x1gb" - by default DDR will run at 1066 MHz. If memory settings are on Auto, your memory will run at SPD settings.

    Calculation: {Memory Multiplier = Round Down ( DDR Speed / BCLK)} Not really. E4500 is a Core2 CPU, uses FSB, not BCLK.
    Sock - Memory Multiplier = (1066 MHz / 133.33 MHz) = 8 No BLCK, doesn't apply.
    therefore Memory Multiplier =(1600 / 133.33) = 12

    BIOS Changes:
    1. Memory Multiplier = 12 {Some BIOS calulate this and give a drop-down menu - {1600 Mhz} If it is a Gigabyte board, take the memory settings off Auto and set Memory Multiplier to 4. That will give you a memory clock four time the FSB frequency, just what you need to run your FSB:RAM ratio at 1:1.

    2. CAS Settings = 7-7-7-16
    3. {Verify Auto} or set DRAM Voltage per spec'd DDR {e.g. 1.65V}

    In any case unless your BIOS fully recognizes you exact Part-Number XMP DDR then don't use XMP; BSOD/Post Failure/Unstable system will result otherwise. Example, XMP {MOBO Certified Memory Support List} - http://www.gigabyte.us/products/product-page.aspx?pid=3449#memory%20support%20list
  3. ^ Yep! - oopsy {1366 vs 775} They are a pain to calculate; I use an Excel spread sheet. Autopilot crash!
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