What is the difference between changing ram frequency and changing FSB

If you keep all the timings the same, what is the difference between 8 multiplier with 200 fsb and 6.66 multiplier with 240 fsb? Should there be any?
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  1. Your question is not very clear...

    If your asking if raising the FSB without raising anything else (dropping RAM and CPU mulitpliers) has an effect on performance, then yes it will.

    Though this effect will be quite small, maybe giving you faster times in benchmarks.

    Though I'm guessing that didn't answer your question...
  2. That is the question I am asking, and while it helps let me tell you what my probem is. I have some memory that is rated 1600mhz with 8-8-8-24-41 timings. I can set this in bois by only changing the ram multiplier to 8 and it is stable and works well. If I then go and change the ram mulitplier to 6.66 and the FSB to 240 (Lowering the CPU ratio as well) I will not even post. I had always that that these 2 ways of setting the ram at 1600mhz where equivalent. I am obviously wrong as one is stable and the other will not post. any help or advise would be greatly appricated.

    Also if anyone has any links to a really good tutorial on exactly what the less commonly used memory timings do maybe I can fiddle a little more and find the problem / difference I am missing.
  3. Best answer
    It is more demanding to run the FSB at 240 instead of 200. Thus you may require more voltage on the FSB for it to run stable. Though I must admit that that is not a large increase.

    Also there is sometimes a problem with motherboards/RAM where they will not run well or at all on some FSB:RAM ratios.
  4. I forget to mention a couple things. First I have run teh FSB at 250 with no problems before with 2 sticks of identical ram (my old sticks). I bought another set of 2 sticks recently (my new sticks). The old sticks run fsb up to 250 no problems. If I replace the old sticks with the new ones (or put all 4 sticks in) It will not post past 210 FSB, even with the ram timings lowers.

    Other things to note: My cpu/NB are both capable of running at 250 fsb w/o changing multipliers. Infact everything seems to be working good except these 2 new sticks cant handle a FSB change and I have no idea why that is. I have a GA-990FXA-UD5 so I have lots of Bios options that should be albe to fix this (at least I hope), but I have no idea where to begin as beyond the first standard ram timings the settings are greek to me.
  5. Best answer selected by Wizardsblade.
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