On 1/17/06, Henk Stokhorst <[EMAIL PROTECTED]> wrote: > > Alasdair Tompson wrote: > > >I saw this in the output screen of one of my clients and wondered what > >it meant: > >Iteration: 18835326/29642771,ERROR:ROUND OFF (0.40625) > 0.40 > >Continuing from last save file. > >Resuming primality test of M29642771 at iteration 18830465 [62.52%] > >Disregard last error. result is reproducible and thus is not a hardware > >problem. > >For added safety, redoing iteration using a slower, more reliable > >method. > >Continuing fom last save file. > >Resuming primality test of M29642771 at iteration 18835319 [63.54%] > > > Probably that your machine gets overheated. Check the temperature of > your processor >
Actually, I believe this type of error comes from the Fast Fourier Transform (FFT) length not being big enough. In Prime95, it occasionally checks the round-off error from doing the FFT required for the multiplication of large numbers during the Lucas-Lehmer test. If it's rounding off more than 0.4from the resultant numbers, it switches to a longer FFT length which is more precise, but takes longer to test. So the error is a most likely due the algorithm, not your hardware. If it was a hardware problem, it is likely that the error would not be reproducible, which it was. The idea is that if your hardware is failing, errors it introduces should be "random," so a specific error shouldn't be reproducible. But then again, I'm no overclocking expert, so I won't make a definitive statement. _______________________________________________ Prime mailing list [email protected] http://hogranch.com/mailman/listinfo/prime
