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memory/cpu/mobo mhz?

By hippy
May 29, 2003
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  1. Any information about mhz and how they relate for cpu, mobo and memory??? Anyone???

    What does it mean when my corsair 256 pc3200 is '400mhz' and how does that effect the cpu and mobo? (cpu = barton 2500 and mobo = abit nf7 v2.0)

    Is there any type of perfect combination of 'mhz' and ALSO how does this effect overclocking???

    :) me good with questions

    Hippy.
  2. MrGaribaldi

    MrGaribaldi TechSpot Ambassador Posts: 2,802

    When you buy a cpu these days, you should make sure your memory runs at the same (or higher) FSB speed, as otherwise your cpu would have to wait a couple of cycles before it could use the memory...
    yes, I know it's a simple explanation, but it gets the point across

    In your case, you've got memory which is faster than your FSB (the barton is running at 333Mhz, and the memory at 400), which is a good thing :)

    As far as overclocking goes, it doesn't really have too much to say, since you'll be pushing the chip/cpu higher than it's rated...
    Then it depends on which company has produced the chips on the dimm (winbod is supposed to be a very good chip manufacturer)...

    Corsair has some types of RAM which is very easy to oc, so you could be lucky... (As Arris, he's got it)

    There isn't any "perfect" combination, but you should try to make sure your memory is equal to or faster than your cpu...
    IMO, it's better to be "clock starved" than "memory starved"...

    Hope this explains some of what you were asking about :)
    (If not, tell us what wasn't clear/wasn't answered and either someone else will tell you what you're looking for, or I'll take another shot :))
  3. Tarkus

    Tarkus TechSpot Ambassador Posts: 837

    Let's see if I can make what I understand make sense to you. Your PC3200(400Mhz) ram is DDR and is rated to run at the specified latencies(2-2-2-5 or 2.5-3-3-7 or whatever) at 2x200FSB or 400 Mhz. Your CPU runs at a a FSB of 166 or 333 Mhz DDR. The CPU speed in Megahertz is based on the FSB times a built in multiplier clock. Let's say you're running 100 Mhz FSB times a 10X multiplier and you get a 1000 Mhz CPU. The multiplier is usually locked in by the manufacturer who locks out access to all the other possible multipliers when they make the chip. The nice thing about the newer boards, like the NF7, is the lower multipliers are available to use. By selecting User defined for your CPU in BIOS you can lower the multiplier and raise the the FSB, there by keeping the CPU in speed spec and bring your board up to the 200 Mhz FSB they are rated for, or you can leave the multiplier where it is and OC your CPU when you bring the board up to it's rated speed.

    It's a lot of trial and error finding the max stable speed for all three components (and peripherals if you happen to have a non locked PCI and/or AGP bus). Anything I left out?
  4. Arris

    Arris TS Evangelist Posts: 4,551   +97

    Geee and I thought it saying OCZ Technologies on the copper heatspreader meant it was OCZ ram ;) (or did you mean the Abit NF7-S v2.0???)

    But as other have said, the ram runs at a double data rate of the fsb. You can specify the divider system so that your ram runs 266DDR and CPU on 333DDR and so on. The ideal maximum bandwidth situation is to have the ram at 400DDR(200fsb) and the CPU at 400DDR(200fsb). Depending on what your ram is rated for you may have to adjust your ram timings down the way to get it stable. Also drop your CPU multiplier so that your not running 13x200 or something else very high Mhz straight away as you will need good cooling to get higher overclocks.

    At the moment I am STILL working on getting my 2100+ Tbred B stable at 10.5x200fsb(2.1Ghz) with fast memory timings. I feel this is my performance sweetspot as going any higher in clock multiplier is giving me too much heat and I don't want to have my ThermalTake SmartFan II on the CPU heatsink screaming like a banshee :p

    As to how well the Barton 2500+ overclocks, as MrGaribaldi, he has it :D
  5. MrGaribaldi

    MrGaribaldi TechSpot Ambassador Posts: 2,802



    :eek: Ooops... I just remembered you had some "special" ram... :eek:

    Not that I've done any thorough testing, but it would seem it oc's very well...

    I ran it at 2800+ speed (and default core) when I first installed it (forgot the correct settings), and it didn't mind too much...
    I got 3 BSOD, but mostly it would just quite SETI on me...

    And from what I've read, it's not to hard to push it above 2800+, though you might need something else thant he stock cooling...
    (Or at least remove the thermal pad and use some good paste...)
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