CPU/Memory Ratio

Discussion in 'General Hardware' started by Jz1397-5, Dec 20, 2002.

  1. Jz1397-5

    Jz1397-5 XP Bad Ass

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    I was looking through my BIOS and saw the CPU/Memory option. Right now it is set to auto, but i have the options of 1:1 and 4:5. What does it do, should i change it?
     
  2. Taurus

    Taurus hardware monkey

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    1:1 means your cpu and memory will both run syncronously at 133mhz.

    4:5 means your cpu will be at 133mhz and your memory will run at 166mhz (pc2700).
     
  3. Jz1397-5

    Jz1397-5 XP Bad Ass

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    so i should change it to 4:5?
     
  4. Taurus

    Taurus hardware monkey

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    yup. but only if the following are true:

    - your memory timings aren't set too low. if you run fast memory at a slower speed (like yours is), it's possible to lower the latency values in the bios for performance... but in order for it to work at a faster speed, you might have to turn up the latency a little bit. if you haven't messed with the timings at all, then disregard this.

    - your fsb isn't overclocked much. a, say, 140mhz fsb would equal 175mhz (350mhz ddr) memory and it probly won't be able to go that high. if your fsb is upped, bring it back down to 133.

    i'd do benchmarking and see which configuration is best. believe it or not, it might be better to have the memory run syncronously with the fsb (133, 1:1) and have low latency timings than to have 166mhz memory with higher timings.
     
  5. Jz1397-5

    Jz1397-5 XP Bad Ass

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    i have noticed slow downs and speed ups, so i will just set it back to auto.