Possible garbage result in M84944207

chuenkit · 2019-07-31, 01:19

I got the message (see attachment) in prime95. Does it mean the result is garbage?

Prime95 · 2019-07-31, 01:40

Quote:

Originally Posted by chuenkit

I got the message (see attachment) in prime95. Does it mean the result is garbage?

Maybe. I guess you have a 50-50 chance of turning in a good result. You're this far in, I'd complete the test.

Get version 29.8. Change your work preference to what-makes-sense or first-time PRP. Error checking during a PRP test will catch every hardware error and repair the fault. Also, if you have any more LL tests queued up, unreserve them.

chuenkit · 2019-07-31, 02:15

Quote:

Originally Posted by Prime95

Maybe. I guess you have a 50-50 chance of turning in a good result. You're this far in, I'd complete the test.

Get version 29.8. Change your work preference to what-makes-sense or first-time PRP. Error checking during a PRP test will catch every hardware error and repair the fault. Also, if you have any more LL tests queued up, unreserve them.

Noted. I think I will move to work on double-checking.

Prime95 · 2019-07-31, 02:56

Quote:

Originally Posted by chuenkit

Noted. I think I will move to work on double-checking.

Flaky hardware can best contribute with first time PRP testing. All hardware errors are caught and corrected.

Double-checking will run LL tests which may or may not catch hardware errors.

kriesel · 2019-07-31, 06:11

Quote:

Originally Posted by Prime95

Flaky hardware can best contribute with first time PRP testing. All hardware errors are caught and corrected.

Double-checking will run LL tests which may or may not catch hardware errors.

Hmm, I see both Double check LL and Double check PRP choices in both the manual assignment page and in prime95 v29.8b3 worker window type of work to get. Have a PRP-DC in progress in prime95.

Prime95 · 2019-07-31, 16:28

Quote:

Originally Posted by kriesel

Hmm, I see both Double check LL and Double check PRP choices in both the manual assignment page and in prime95 v29.8b3 worker window type of work to get. Have a PRP-DC in progress in prime95.

Yes, PRP-DC is also a suitable work preference. However, you will be testing numbers of approximately the same size. First time PRP only started a about a year ago with exponents in the 80 millions.

kriesel · 2019-07-31, 18:32

I think it's great any time someone is willing to chip away at the big backlog of LL-DC. And also when anyone is willing to contribute some PRP-DC, which are relatively scarce, so there's not much sample size for seeing any possible escapes of errors from the excellent Gerbicz Error Check and code surrounding it. As I recall, George did a code review a while back and found some possible cases, since fixed. Gpuowl PRP has been available for about 2 years and was running 4M fft around 75M up to 78M as I recall.

GP2 · 2019-07-31, 19:32

Quote:

Originally Posted by Prime95

Flaky hardware can best contribute with first time PRP testing. All hardware errors are caught and corrected.

Double-checking will run LL tests which may or may not catch hardware errors.

Maybe flaky hardware can contribute most by doing PRP double checks, to help verify that the new improved error checking really is bulletproof.

Prime95 · 2019-07-31, 19:59

Quote:

Originally Posted by GP2

Maybe flaky hardware can contribute most by doing PRP double checks, to help verify that the new improved error checking really is bulletproof.

I agree with all that has been said. My post came across as poo-poo-ing PRP-DC work. That was a mistake. I was trying to give the user more info for making his choice.

We all agree that PRP or PRP-DC work is the best choice.

1) First-time PRP work will get exponents around 89 million. Best chance of finding a new prime.
2) Double-check PRP work will get exponents around 80 million, well ahead of the LL-DC wavefront. Poor chance of finding a new prime. Work is especially useful to verify the quality of early PRP error checking implementations.

dcheuk · 2019-07-31, 20:31

Quote:

Originally Posted by chuenkit

I got the message (see attachment) in prime95. Does it mean the result is garbage?

Running a double check on this, eta 4 days.

dcheuk · 2019-08-05, 00:19

Successful DC. Horray!

(This links to exponent status of M84944207)
https://www.mersenne.org/report_expo...4944207&full=1

And with that completed, I believe all exponents below 85 million have been checked at least once.

Double Hooray!!

2019-07-31, 01:19	#1
chuenkit Jul 2018 2² Posts	Possible garbage result in M84944207 I got the message (see attachment) in prime95. Does it mean the result is garbage? Attached Thumbnails

2019-07-31, 18:32	#7
kriesel "TF79LL86GIMPS96gpu17" Mar 2017 US midwest 2⁴×3×163 Posts	I think it's great any time someone is willing to chip away at the big backlog of LL-DC. And also when anyone is willing to contribute some PRP-DC, which are relatively scarce, so there's not much sample size for seeing any possible escapes of errors from the excellent Gerbicz Error Check and code surrounding it. As I recall, George did a code review a while back and found some possible cases, since fixed. Gpuowl PRP has been available for about 2 years and was running 4M fft around 75M up to 78M as I recall. Last fiddled with by kriesel on 2019-07-31 at 18:44

2019-08-05, 00:19	#11
dcheuk Jan 2019 Florida 243₁₀ Posts	Successful DC. Horray! (This links to exponent status of M84944207) https://www.mersenne.org/report_expo...4944207&full=1 And with that completed, I believe all exponents below 85 million have been checked at least once. Double Hooray!! Last fiddled with by dcheuk on 2019-08-05 at 00:21 Reason: Grammatical error

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