FSB:DRAM CPU/Memory OC is way over my head

I am a first time overclocker. I've had my rig for 2 years but was tempted when I got my new video card. That was simple enough to OC.

My issue is that I don't understand the OC process for memory. I read that the fsb:dram ratio matter and some say it doesn't. I don't know what to believe.

My cpu (listed in sig) has a fsb of 1333 and I am running ddr2-800 memory. What I understand is that to have a 1:1 clock cycle the ram would only have to be ddr2-667.

Basically I don't know what to do. What I think I am suppose to do is OC the FSB up to or as close as I can get to 400 and leave the memory alone. If this is true do you think my system will be able to OC the bus from 333 to 400? If this isn't what I am suppose to be doing please let me know how I should go about OCing the CPU and memory.

Also I read that you have to take the multiplier down on the memory when you start OCing the cpu. What does this mean and do?

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  1. It's not going to be a big deal, faster CPU will give noticeable benefits while faster or optimal memory ratios will be fairly negligible. Anyway, you want to reduce the RAM speed (via ratio) when OCing the CPU because as you raise the FSB for CPU OC it raises the RAM speed as well... and RAM doesn't like too much OCing at a given CAS Latency. So either raise the CL by 1 or reduce it's overall speed. However, I would say try getting the FSB stable at 400 and get that "optimal" performance. I don't know about your specific core, but I've read plenty of people get that fairly easily... it's only a 20% increase, afterall. Then you can set the RAM to it's optimal speed and get that golden 1:1. You can try setting it to 400 with lower CPU multiplier and see if it's stable, then slowly increase the multiplier to get whatever speed you're aiming for... or if not aiming, just as high as your comfortable which should mostly depend on temps and voltages (stay within voltage specs - check the Intel site for documentation)
  2. Thanks for the info. I think I got it figured out alright. I set the FSB to 425 and the ram to 850 to get the 1:1.

    Is it worthwhile to Overclock the Ram higher if I didn't want to move the FSB anymore? Also this is a bit off topic for memory OC forum but should I let my bios auto-set the cpu voltage as I overclock the fsb up?
  3. To maximize the RAM, you want to get as much speed out of it at a given Latency. In my experience I can't get more than about 20mhz above RAM spec. Granted, it's DDR3 but as an example, 1600mzh CL8 spec I could have stable at 1620 CL8 but 1630 CL8 was unstable. So yes, a little more speed without chaning the latency is "better" but again, RAM speed is quite negligible. You probably won't gain 1FPS in gaming from doing this. It's more important to have the CPU OCed to your liking.

    As for voltages, I would use the auto settings as a guideline but set them manually. Often the auto setting overvolts a bit, and sometimes your hardware is able to undervolt and save some power, heat, and possibly extend life.

    Do you know how to test your OC?
  4. No I don't know how to stress test the gpu or memory. I figure it takes some sort of stress test or benchmark software like furmark for a GPU?

    I went with what seems to be slightly under stable for my components from what I have seen others post on the net.
    Right now I have it set at 850(425) memory to get it to 1:1 with my FSB at 1700 for my q9450(x8 multi) putting it at 3.4.

    I would appreciate the how-to stress test, cpu and memory for that matter, so I can put them at better voltages or possibly clock higher.
    If it helps I have my ram at 2.1 volts which a tom's hardware test for that stick said was recommended and the bios is auto volting the cpu to 1.32.


    PS: When I overclock the cpu and have the bios link the fsb to memory at 1:1 it sets the memory at double what it should be as if it weren't ddr. Should I just set it manually each time I move the FSB clocks to keep it at 1:1 myself?
  5. Use Prime95 to test your CPU/Memory. You can also use Memtest86 to test just your memory, but Prime95 is usually sufficient/easier.

    I'd turn off any auto settings in bios on voltages. 1.32v is probably a lot more than you need.
  6. First of all, set your system to the 1:1 ratio. Don't worry about overclocking memory. OC'ing memory adds little if anything to system performance. One place we talk about that is here:
  7. Thanks for the responses.

    If my 800 memory is only gonna overclock to about lets say 900 just for round numbers. There would be no sense in pushing the FSB past 1800 right because then the memory is bottlenecking the rest of the system?
  8. Also if any of you smart computer guys come back and don't mind answering a few more memory questions for me.

    Cas 4 and Cas 5 whats the difference/what the hell does it mean? I think it means you can set the timings to like 4-4-4-x?

    My sticks are suppose to run 5-5-5-15. A review said run it at 5-5-5-16. I understand playing with that last one can affect performance ie 15, 16 ,17. How do I know what to set it at?

    Thanks again
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