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Thread: Passing memtest but not IBT

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    Senior Member AD-15's Avatar
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    Passing memtest but not IBT


    I recently tested a new OC on my core i7 system. The CPU is stable, but when I started to bring the RAM latencies back down (I had them high for stability testing), the system stopped being stable uner Intel Burn Test.

    However, running memtest, I get no errors at all after several passes. So the RAM itself is stable.

    Does this mean the interface between the CPU and RAM is not able to handle the higher data rates due to the high clock/low latency? Would the solution to this be increasing the CPU VTT voltage?

    EDIT: All the ratios are correct, UNCORE:RAM is 2:1, QPI:UNCORE is 9:8 etc.
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    Moderator chuckskull's Avatar
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    Re: Passing memtest but not IBT

    OC'ing isn't always a cut and dry business. Sometimes things that by all rights should work, just wont. My E4300 for example just will not work between about 2.4 and 3.0ghz, no matter how much juice you give it, but works fine over 3.0, with only a slight bump in voltage from stock.

    Also worth remembering that while memtest is very good, it's not infallible, IBT might be finding an error that memtest isn't or there could be another weakness in-between the ram and CPU, like you said. Could also be vdroop somewhere in the system that's not so severe when only the ram is under strain.

    If your voltages aren't to high already, then more volts in the NB or CPU is always worth a shot. Failing that, just loosen the timings on the ram a little. The performance difference will only be slight.

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