mersenneforum.org  

Go Back   mersenneforum.org > Extra Stuff > Linux

Reply
 
Thread Tools
Old 2009-05-07, 13:49   #1
graysky
 
graysky's Avatar
 
Jul 2004

41 Posts
Default option for round off checking in linux64 version?

I have used p95 under Windows before for the purpose of stability checking. I remember seeing an option under the “Advanced” menu and called “Round off Checking.” As I recall, this needed to be set to enable or else errors wouldn't be reported. I'm running the mprime259_linux64 version of p95 now under a 64-bit Linux OS and can't for the life of me find that round off checking option anywhere.

I'm doing the blend test to test out my new memory but am wondering if errors will get reported as-is?
graysky is offline   Reply With Quote
Old 2009-05-07, 14:33   #2
cheesehead
 
cheesehead's Avatar
 
"Richard B. Woods"
Aug 2002
Wisconsin USA

170148 Posts
Default

Quote:
Originally Posted by graysky View Post
I have used p95 under Windows before for the purpose of stability checking. I remember seeing an option under the “Advanced” menu and called “Round off Checking.” As I recall, this needed to be set to enable or else errors wouldn't be reported. I'm running the mprime259_linux64 version of p95 now under a 64-bit Linux OS and can't for the life of me find that round off checking option anywhere.

I'm doing the blend test to test out my new memory but am wondering if errors will get reported as-is?
Don't worry. "Round Off Checking" just means that extra checking, beyond the standard amount, will be done, and that the roundoff error amount, no matter how nonthreatening, will be reported on your iteration lines. Small roundoff errors in the 0.00-0.09 range are routine and don't threaten the accuracy of our integer results.

If there is a roundoff error that is big enough (> 0.2 or so) to actually imperil the accuracy of the calculation, it'll get reported no matter what "Round Off Checking" is set to.

When you observed that "this needed to be set to enable or else errors wouldn't be reported", the missing clarification was that instead of having only threateningly-large errors being reported as is the default, "Round Off Checking" caused all errors, no matter how small or inconsequential, to be reported.

As for whether the mprime259_linux64 version of p95 has that option, and where it is: I don't know.

Last fiddled with by cheesehead on 2009-05-07 at 14:45
cheesehead is offline   Reply With Quote
Old 2009-05-07, 14:43   #3
Prime95
P90 years forever!
 
Prime95's Avatar
 
Aug 2002
Yeehaw, FL

72·149 Posts
Default

Round-off checking refers to extra error checking that an ordinary user can insist on when processing work units.

You are doing a torture test rather than processing work units. The torture test will catch any errors that occur during computations. The results of each test are compared to known good results.
Prime95 is offline   Reply With Quote
Old 2009-05-07, 14:43   #4
graysky
 
graysky's Avatar
 
Jul 2004

2916 Posts
Default

Thanks for the quick replies, all. It sounds like my stress test will be valid w/ the default options then.

Last fiddled with by graysky on 2009-05-07 at 14:45
graysky is offline   Reply With Quote
Reply

Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Advanced round off checking wingman99 Information & Answers 3 2017-02-18 05:47
In Prime95 linux64, "make clean" deletes factor64.o while it shouldn't. Explorer09 Software 1 2014-08-18 19:44
Round Off Checking and Sum (Inputs) Error Checking Forceman Software 2 2013-01-30 17:32
Linux64 v25.11 not trusted? TheJudger PrimeNet 6 2010-09-02 23:39
Round off checking - on or off? Nuppi Software 6 2010-09-01 17:10

All times are UTC. The time now is 21:58.

Tue Jan 19 21:58:28 UTC 2021 up 47 days, 18:09, 0 users, load averages: 1.47, 1.63, 1.66

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.