mersenneforum.org  

Go Back   mersenneforum.org > Great Internet Mersenne Prime Search > Software

Reply
 
Thread Tools
Old 2003-08-01, 06:19   #1
NookieN
 
NookieN's Avatar
 
Aug 2002

59 Posts
Default M19 is not prime...

Well ok obviously it is. But for some reason one of my copies of Prime95 says it isn't about 10% of the time.

I was running a torture test with w23.4 on a P4 with HT enabled. While the torture test was running I decided to play around with another instance of Prime. I tried LL testing several known Mersenne primes for fun. M216091, M132049, M110503 all came out fine. Then I entered M19 and got this:

UID: ....../C6CA6CD00, M19 is not prime. Res64: FFFFFFFFFFFFFFFF. WZ1: 00260028,16,00000000

I wasn't exactly expecting that. I tried testing it again and it came out as prime several times. Then I tested M19937 followed by M19 again:

UID: ....../C6CA6CD00, M19937 is prime! WZ1: 51779BC2
UID: ....../C6CA6CD00, M19 is not prime. Res64: FFFFFFFFFFFFFFFF. WZ1: 00260028,16,00000000

Obviously this isn't really a problem since Prime isn't meant to test numbers this small. I don't think it could be a hardware issue on my system as the TT is still chugging away. Anyone else ever seen the before? Is this just due to SSE2 rounding, or there something else that could cause the residual to occasionally be all ones?
NookieN is offline   Reply With Quote
Old 2003-08-01, 06:40   #2
kwstone
 
kwstone's Avatar
 
Jun 2003
Shanghai, China

109 Posts
Default

I get M19 is not prime too. So it's not just your machine.
kwstone is offline   Reply With Quote
Old 2003-08-01, 06:55   #3
ColdFury
 
ColdFury's Avatar
 
Aug 2002

26×5 Posts
Default

I believe George has mentioned before that at very low exponents, the code doesn't always work correctly.
ColdFury is offline   Reply With Quote
Old 2003-08-01, 07:09   #4
Xyzzy
 
Xyzzy's Avatar
 
Aug 2002

23×1,051 Posts
Default

http://arstechnica.infopop.net/OpenTopic/page?a=tpc&s=50009562&f=122097561&m=3300925355&r=1820975755#1820975755
Xyzzy is offline   Reply With Quote
Old 2003-08-01, 10:03   #5
TTn
 

905810 Posts
Default

And very large exponents too.
  Reply With Quote
Old 2003-08-01, 10:37   #6
smh
 
smh's Avatar
 
"Sander"
Oct 2002
52.345322,5.52471

29·41 Posts
Default

Quote:
Originally Posted by TTn
And very large exponents too.
Based on what?

I think it has been explained several times to you that the machine where the supposed M40 was running on had hardware problems!

I think it's about time that you should stop making thes unfounded statements.
smh is offline   Reply With Quote
Old 2003-08-01, 12:50   #7
lycorn
 
lycorn's Avatar
 
"GIMFS"
Sep 2002
Oeiras, Portugal

22·3·127 Posts
Default

Quote:
Originally Posted by TTn
And very large exponents too.
Do you mean > 79.3M?
If that is the case, it is not a question of "not working correctly". It´s just that the current version of the program is not meant to test exponents above that limit. With today´s technology, it would be useless anyway... 8). We have already enough exponents to keep us all busy for the next 10 or 15 years :)
lycorn is offline   Reply With Quote
Old 2003-08-01, 17:41   #8
ColdFury
 
ColdFury's Avatar
 
Aug 2002

26×5 Posts
Default

Quote:
And very large exponents too.
Just couldn't resist could you? Keep beating that long dead horse.
ColdFury is offline   Reply With Quote
Old 2003-08-01, 18:31   #9
Paulie
 
Paulie's Avatar
 
Aug 2002

223 Posts
Default

Quote:
Originally Posted by smh
Quote:
Originally Posted by TTn
And very large exponents too.
Based on what?

I think it has been explained several times to you that the machine where the supposed M40 was running on had hardware problems!

I think it's about time that you should stop making thes unfounded statements.
It's way past the time. But the person in question likes being a jerk, so what can you expect. Sad really...
Paulie is offline   Reply With Quote
Old 2003-08-01, 22:28   #10
TTn
 

23×7×61 Posts
Default

Actually its in the source.
You guys are the jerks.
Should we have a poll to kick you guys out!
Or wait a poll to stop GIMPS because you guys were jerks..
Ya ya thats the ticket!

I did not mention M40, but you retards automatically thought that is what I was saying.
  Reply With Quote
Old 2003-08-01, 22:34   #11
nomadicus
 
nomadicus's Avatar
 
Jan 2003
North Carolina

2×3×41 Posts
Default

We love you TTn inspite of the name calling. :mrgreen:
Quote:
Originally Posted by TTn
You guys are the jerks.
nomadicus is offline   Reply With Quote
Reply

Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
(M48) NEW MERSENNE PRIME! LARGEST PRIME NUMBER DISCOVERED! dabaichi News 571 2020-10-26 11:02
Twin Prime Days, Prime Day Clusters cuBerBruce Puzzles 3 2014-12-01 18:15
disk died, prime work lost forever? where to put prime? on SSD or HDD? emily PrimeNet 3 2013-03-01 05:49
Prime Cullen Prime, Rest in Peace hhh Prime Cullen Prime 4 2007-09-21 16:34
The 40th known Mersenne prime, 220996011-1 is not PRIME! illman-q Miscellaneous Math 33 2004-09-19 05:02

All times are UTC. The time now is 20:43.


Sat Jan 22 20:43:12 UTC 2022 up 183 days, 15:12, 0 users, load averages: 1.79, 1.83, 1.90

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2022, 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.

≠ ± ∓ ÷ × · − √ ‰ ⊗ ⊕ ⊖ ⊘ ⊙ ≤ ≥ ≦ ≧ ≨ ≩ ≺ ≻ ≼ ≽ ⊏ ⊐ ⊑ ⊒ ² ³ °
∠ ∟ ° ≅ ~ ‖ ⟂ ⫛
≡ ≜ ≈ ∝ ∞ ≪ ≫ ⌊⌋ ⌈⌉ ∘ ∏ ∐ ∑ ∧ ∨ ∩ ∪ ⨀ ⊕ ⊗ 𝖕 𝖖 𝖗 ⊲ ⊳
∅ ∖ ∁ ↦ ↣ ∩ ∪ ⊆ ⊂ ⊄ ⊊ ⊇ ⊃ ⊅ ⊋ ⊖ ∈ ∉ ∋ ∌ ℕ ℤ ℚ ℝ ℂ ℵ ℶ ℷ ℸ 𝓟
¬ ∨ ∧ ⊕ → ← ⇒ ⇐ ⇔ ∀ ∃ ∄ ∴ ∵ ⊤ ⊥ ⊢ ⊨ ⫤ ⊣ … ⋯ ⋮ ⋰ ⋱
∫ ∬ ∭ ∮ ∯ ∰ ∇ ∆ δ ∂ ℱ ℒ ℓ
𝛢𝛼 𝛣𝛽 𝛤𝛾 𝛥𝛿 𝛦𝜀𝜖 𝛧𝜁 𝛨𝜂 𝛩𝜃𝜗 𝛪𝜄 𝛫𝜅 𝛬𝜆 𝛭𝜇 𝛮𝜈 𝛯𝜉 𝛰𝜊 𝛱𝜋 𝛲𝜌 𝛴𝜎 𝛵𝜏 𝛶𝜐 𝛷𝜙𝜑 𝛸𝜒 𝛹𝜓 𝛺𝜔