mersenneforum.org  

Go Back   mersenneforum.org > Great Internet Mersenne Prime Search > Hardware > GPU Computing

Reply
 
Thread Tools
Old 2019-04-25, 22:34   #1
Prime95
P90 years forever!
 
Prime95's Avatar
 
Aug 2002
Yeehaw, FL

22·17·109 Posts
Default mfaktc bug?

This was submitted by a reliable user:

no factor for M384000053 from 2^76 to 2^77 [mfaktc 0.21 barrett76_mul32_gs]

Note that mfaktc used a barrett76 kernel to TF to 2^77. Bug?
Prime95 is offline   Reply With Quote
Old 2019-04-25, 23:13   #2
srow7
 
Jul 2014

3×17 Posts
Default

I got barrett87_mul32_gs
using mfaktc 0.21
CUDA driver 9.10
eta 1hr
srow7 is online now   Reply With Quote
Old 2019-04-26, 01:21   #3
kriesel
 
kriesel's Avatar
 
"TF79LL86GIMPS96gpu17"
Mar 2017
US midwest

32×13×43 Posts
Default

Quote:
Originally Posted by Prime95 View Post
This was submitted by a reliable user:

no factor for M384000053 from 2^76 to 2^77 [mfaktc 0.21 barrett76_mul32_gs]

Note that mfaktc used a barrett76 kernel to TF to 2^77. Bug?
Failed to replicate here, with GTX 1080 Ti, mfaktc v0.21 CUDA 8. I tried to tempt it with
Factor=384000053,75,77.

Code:
Apr 25 19:47 | 4612  99.9% |  1.562   0m02s |   1148.18    90677    n.a.%
Apr 25 19:47 | 4615 100.0% |  1.571   0m00s |   1141.60    90677    n.a.%
no factor for M384000053 from 2^75 to 2^76 [mfaktc 0.21 barrett76_mul32_gs]
tf(): total time spent: 25m  4.678s

Starting trial factoring M384000053 from 2^76 to 2^77 (39.85 GHz-days)
 k_min =  98382621478680
 k_max =  196765242961865
Using GPU kernel "barrett87_mul32_gs"
Date    Time | class   Pct |   time     ETA | GHz-d/day    Sieve     Wait
Apr 25 19:47 |    0   0.1% |  3.196  51m05s |   1122.31    90677    n.a.%
  Apr 25 19:47 |    3   0.2% |  3.398  54m15s |   1055.60    90677    n.a.%
Is it possible it's a copy/paste error?
Code:
UID: Kriesel/condorette-gtx1070, no factor for M153500033 from 2^77 to 2^78 [mfaktc 0.21 barrett87_mul32_gs]
UID: Kriesel/condorette-gtx1070, no factor for M149447533 from 2^73 to 2^74 [mfaktc 0.21 barrett76_mul32_gs]
becomes
Code:
UID: Kriesel/condorette-gtx1070, no factor for M153500033 from 2^77 to 2^78 [mfaktc 0.21 barrett76_mul32_gs]
via an accidental deletion of the bold text.

Last fiddled with by kriesel on 2019-04-26 at 01:34
kriesel is online now   Reply With Quote
Old 2019-04-26, 03:28   #4
Madpoo
Serpentine Vermin Jar
 
Madpoo's Avatar
 
Jul 2014

37·89 Posts
Default

Quote:
Originally Posted by kriesel View Post
...Is it possible it's a copy/paste error?...
I don't know. It seems unlikely, and the user kept trying to submit the results over and over (because the server was correctly rejecting the impossible result).

Tried submitting it 4 times I think, and the last attempt had a mix of other TF results. The others were TF to 72 - 75 bits with the same "mfaktc 0.21 barrett76_mul32_gs" client string, but that one result to 77 bits from the 76-bit client ... that's definitely strange.

Like George said, it's a user that we wouldn't expect to try anything fishy, thus wondering if it's some strange bug in the client that mysteriously allowed it.
Madpoo is offline   Reply With Quote
Old 2019-04-26, 03:58   #5
dcheuk
 
dcheuk's Avatar
 
Jan 2019
Tallahassee, FL

257 Posts
Default

Code:
got assignment: exp=384000053 bit_min=76 bit_max=77 (39.85 GHz-days)
Starting trial factoring M384000053 from 2^76 to 2^77 (39.85 GHz-days)
 k_min =  98382621478680
 k_max =  196765242961865
Using GPU kernel "barrett87_mul32_gs"
Date    Time | class   Pct |   time     ETA | GHz-d/day    Sieve     Wait
Apr 25 22:55 |    0   0.1% |  1.504  24m02s |   2384.92    82485    n.a.%
Apr 25 22:55 |    3   0.2% |  1.548  24m43s |   2317.13    82485    n.a.%
Apr 25 22:55 |    7   0.3% |  1.455  23m12s |   2465.23    82485    n.a.%
Like Kriesel said, probably a copy and paste error.

Just read Madpoo's comment. Maybe the user submitted it with lots of other ones but found the server rejected that specific one? Then tried to submit it like 4 more times?
Maybe ask the user directly to see if the result.txt is still intact?

Last fiddled with by dcheuk on 2019-04-26 at 04:12
dcheuk is offline   Reply With Quote
Old 2019-04-26, 05:45   #6
LaurV
Romulan Interpreter
 
LaurV's Avatar
 
Jun 2011
Thailand

11×853 Posts
Default

Can't replicate it here either.

Was an IP address check done? As it is not difficult to send results in the name of other user (we did it in the past, for "credit trade"), maybe someone is trying to discredit somebody else?
Or contact the user and ask?
LaurV is offline   Reply With Quote
Reply

Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Lowering lag on mfaktc possible? manfred4 GPU Computing 6 2014-08-21 15:24
mfaktc not starting in Mac OSX bayanne GPU Computing 0 2014-05-10 14:38
mfaktc on a Mac bayanne GPU Computing 0 2013-10-18 09:59
mfaktc (0.20) fairsky Software 9 2013-09-24 12:58
mfaktc tichy GPU Computing 4 2010-12-03 21:51

All times are UTC. The time now is 11:34.

Tue Apr 20 11:34:44 UTC 2021 up 12 days, 6:15, 0 users, load averages: 1.78, 1.96, 1.95

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.

This forum has received and complied with 0 (zero) government requests for information.

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation.
A copy of the license is included in the FAQ.