Pls i need an advise about frequencies!

I have an Asus M2NPV-VM with DDR2 800MHZ Kingmax 4-4-4-12. The motherboard has 1ghz hypertransport. How should i set the memory frequencies in bios to perfectly match with the motherboard bus. Should i leave it to run at 800Mhz or set it to 400Mhz?
the motherboard hypertransport multiplier is 5x. So the real clock bus is 200Mhz. If the memory runs @ 800Mhz the real clock is 400Mhz. isn`t it too much to match the motherboard bus?
i was reading something about bottlenecks if frequencies are too high or to low and not the same with the motherboard bus.
i`m really confused... :roll:

thanks in advance!
3 answers Last reply
More about advise frequencies
  1. We need to know what your processor is.
    Please list complete specs of your system.
  2. AMD 3500+ Athlon64
    CPU Properties:
    CPU Type AMD Athlon 64, 2200 MHz (11 x 200)
    Instruction Set x86, x86-64, MMX, 3DNow!, SSE, SSE2, SSE3
    Original Clock 2200 MHz
    Min / Max CPU Multiplier 4x / 11x
    L1 Code Cache 64 KB (Parity)
    L1 Data Cache 64 KB (ECC)
    L2 Cache 512 KB (On-Die, ECC, Full-Speed)
    Motherboard Properties:
    Motherboard ID 08/25/2006-C51PV-MCP51-M2NPV-VM-00
    Motherboard Name Asus M2NPV-VM

    Front Side Bus Properties:
    Bus Type AMD Hammer
    Real Clock 200 MHz
    Effective Clock 200 MHz
    HyperTransport Clock 1000 MHz

    Memory Bus Properties:
    Bus Type DDR2 SDRAM
    Bus Width 64-bit
    DRAM:FSB Ratio CPU/6
    Real Clock 368 MHz (DDR)
    Effective Clock 737 MHz
    Bandwidth 5894 MB/s


    Memory Timings:
    CAS Latency (CL) 4T
    RAS To CAS Delay (tRCD) 4T
    RAS Precharge (tRP) 4T
    RAS Active Time (tRAS) 12T
    Row Cycle Time (tRC) 24T
    Command Rate (CR) 2T
    RAS To RAS Delay (tRRD) 3T
    Write Recovery Time (tWR) 6T
    Write To Read Delay (tWTR) 3T
    Refresh Period (tREF) 3.9 us
    DRAM Drive Strength Normal
    Max Async Latency 5 ns
    Idle Cycle Limit 16
    Dynamic Idle Cycle Counter Enabled
    Read/Write Queue Bypass 16

    about motheroard specs here is the link
  3. AMD processors dont run the memory off of the chipset, they are frequency divided off of the CPU frequency.

    Be aware, if you are talking about AM2 CPU's (I assume becase you are quoting DDR2 and HT speeds) then some AM2 CPU speeds will underclock your memory.

    I know that using 800MHz ram the 4200 & 4800 X2 CPU's underclock the ram but the 4600 ones run it at 800MHz. The Clock speeds of 2.2, 2.6, 3.0 would all underclock. 2.4, 2.8 and 3.2 GHz (when released) will not underclock. This is simply because AMD removed the half memory frequency dividers on the AM2 chips.

    The way I got around this is simply to raise the HT clock speed on a 2.2GHz CPU to 220MHz, this will give you 2.4GHz CPU and true 800MHz memory clock.
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