Mersenne: error in V19??!?
Whoops!!! Welcome to GIMPS Prime95 v19, with remote message notification. -- George Scott [Thu Sep 09 20:20:31 1999] Factoring M6539111 to 2^63 is 13.93% complete. [Fri Sep 10 04:58:58 1999] UID: jp/p3-500, M6539111 no factor to 2^63, WV1: 3ED32B8A [Fri Sep 10 06:21:31 1999] Factoring M6779911 to 2^63 is 14.45% complete. [Fri Sep 10 13:57:40 1999] UID: jp/p3-500, M6779911 no factor to 2^63, WV1: 41132D24 [Fri Sep 10 15:17:10 1999] Factoring M8329537 to 2^64 is 8.87% complete. [Sat Sep 11 05:24:12 1999] UID: jp/p3-500, M8329537 no factor to 2^64, WV1: 4FFD3775 [Sat Sep 11 08:19:02 1999] Iteration 670 / 7817869 [Sat Sep 11 10:34:45 1999] Iteration: 6742784/7817869, ERROR: ROUND OFF (0.4086303711) 0.40 Possible hardware failure, consult the readme file. Continuing from last save file. [Sat Sep 11 11:04:20 1999] Disregard last error. Result is reproducible and thus not a hardware problem. Iteration: 6742912/7817869, ERROR: ROUND OFF (0.4086303711) 0.40 Possible hardware failure, consult the readme file. Continuing from last save file. [worktodo.ini is... Test=7817869,63 Test=7888367,63 Test=6539111,63 Test=6779911,63 Test=7468187,63 Test=8329537,64 local.ini is CPUType=10 CPUSpeed=504 SelfTest64Passed=0 SelfTest80Passed=0 SelfTest96Passed=0 SelfTest112Passed=0 SelfTest128Passed=0 SelfTest160Passed=0 SelfTest192Passed=0 SelfTest224Passed=0 SelfTest256Passed=0 ComputerID=p3-500 CPUHours=24 OldRollingAverage=1386 LastEndDatesSent=936928821 RollingStartTime=0 SelfTest384Passed=1 RollingAverage=997 BroadcastID=1 _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Re: Mersenne: error in V19??!?
Hi John, At 11:08 AM 9/11/99 -0700, John R Pierce wrote: Iteration: 6742784/7817869, ERROR: ROUND OFF (0.4086303711) 0.40 Possible hardware failure, consult the readme file. Continuing from last save file. [Sat Sep 11 11:04:20 1999] Disregard last error. Result is reproducible and thus not a hardware problem. Iteration: 6742912/7817869, ERROR: ROUND OFF (0.4086303711) 0.40 Possible hardware failure, consult the readme file. Continuing from last save file. This is not a bug. Brian was right that v19 would ordinarily use a 448K FFT wheras v18 used a 384K FFT. However, v19 is finishing off your exponent using a 384K FFT. You now see why I was a little more conservative with the FFT crossover points. Your 0.4086 error is not much greater than 0.4 and not near the 0.5 error that would corrupt your result. I'd continue onward with your test - you probably would have gotten the same error in version 18. Regards, George _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Re: Mersenne: error in V19??!?
This is not a bug. Brian was right that v19 would ordinarily use a 448K FFT wheras v18 used a 384K FFT. However, v19 is finishing off your exponent using a 384K FFT. You now see why I was a little more conservative with the FFT crossover points. Your 0.4086 error is not much greater than 0.4 and not near the 0.5 error that would corrupt your result. I'd continue onward with your test - you probably would have gotten the same error in version 18. ah. yer right. I looked back in my results.txt and found... [Sun Sep 05 02:42:01 1999] Iteration: 4647424/7817869, ERROR: ROUND OFF (0.4007873535) 0.40 Possible hardware failure, consult the readme file. Continuing from last save file. [Sun Sep 05 03:01:47 1999] Disregard last error. Result is reproducible and thus not a hardware problem. this was with v18... Must just be something funky about this particular candidate, not one other one I've run on this system has triggered this same error (I've been running prime95 24/7 since June on this box) [Sat Jun 26 05:38:31 1999] UID: jp/p3-500, M7636493 is not prime. Res64: B1B90297D4483A26. WU1: AD93C932,1209352, [Wed Jul 14 04:06:17 1999] UID: jp/p3-500, M7636561 is not prime. Res64: 07124E50AF70224A. WU1: 9ADED520,5521093, [Sat Jul 31 02:52:42 1999] UID: jp/p3-500, M7636597 is not prime. Res64: D1ED8948161F652F. WU1: C42D91B1,7404799, [Fri Aug 20 20:36:32 1999] UID: jp/p3-500, M7539533 is not prime. Res64: 3CE1193877330039. WU1: A4347C02,0,8000 [Tue Aug 24 08:06:32 1999] UID: jp/p3-500, M7666597 is not prime. Res64: DB189558BA6AD87F. WU1: 0FA06293,6759810, _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
