mersenneforum.org  

Go Back   mersenneforum.org > Other Stuff > Archived Projects > PSearch

 
 
Thread Tools
Old 2004-07-29, 18:59   #1
Prime95
P90 years forever!
 
Prime95's Avatar
 
Aug 2002
Yeehaw, FL

701410 Posts
Default Beta version of PRP

There is a new version of PRP available for testing. It only works on SSE2 machines and should be much faster. It would be great some of you could test it out - especially important would be a few retests to make sure it generates matching residues.

Windows only for now: ftp://mersenne.org/gimps/prp3.zip
Prime95 is online now  
Old 2004-07-29, 20:37   #2
ltd
 
ltd's Avatar
 
Apr 2003

77210 Posts
Default

I will do some tests with some of the psp numbers.( At first some low n)

My first observation was that it was slower then prp.exe

PRP.exe gave me 0.92mS per bit
PRP3.exe gives 1.234mS per bit for the same test.

Correction:
now it gives sometimes 0.573mS per bit.
The runtime is not stable: It moves between 0.57 and 1.2 mS. (most of the time >1.0mS)
The software runs on a P4 HT 3.0GHz with WinXP.
There is another DC project runing in parallel.(eulernet)
The same configurtion runs with prp.exe without changing times.

Lars

Last fiddled with by ltd on 2004-07-29 at 20:45
ltd is offline  
Old 2004-07-29, 20:47   #3
ltd
 
ltd's Avatar
 
Apr 2003

22·193 Posts
Default

One additional question which residue is the one i should use to compare with prp.exe. "Res64" or "old64" ???

Lars
ltd is offline  
Old 2004-07-29, 20:57   #4
Prime95
P90 years forever!
 
Prime95's Avatar
 
Aug 2002
Yeehaw, FL

11011011001102 Posts
Default

old64 should match the old prp.exe. THe new res64 is compatible with PFGW.
Prime95 is online now  
Old 2004-07-29, 21:03   #5
ltd
 
ltd's Avatar
 
Apr 2003

11000001002 Posts
Default

Yep found that out too.

My next report on PRP3.

I made 20 tests with an FFT length of 16k.
All residues are identical with the original residues i found in the PSP database. ( The original calculation was done by a user which used llr.exe)

I made also test if there are problems when i stop PRP3.exe whitin a calculation and found no problems yet.

Only problem i have is that it is not continuosly fast.
Most of the time it is slower then prp.exe on my system.

Lars
ltd is offline  
Old 2004-07-29, 21:39   #6
ltd
 
ltd's Avatar
 
Apr 2003

22×193 Posts
Default

OK i think i found a reason for the different speeds.
It is to warm here and so the PC (a notebook) slows down to secure itself from overheating.
Seems to be the case as at the moment prp.exe also shows differnt speeds which is normaly not happening.

Lars

Last fiddled with by ltd on 2004-07-29 at 21:40
ltd is offline  
Old 2004-07-30, 11:06   #7
Thomas11
 
Thomas11's Avatar
 
Feb 2003

77116 Posts
Default

I've found two bugs so far:


The first is a minor one. If the sieve depth is greater than 2^32, than the value stored in the headline of the output file doesn't match that one from the input file, e.g. 37572480860218 -> 106954810


The second one is a bit serious. I'm getting a ROUND OFF error while testing 3*2^234760-1:

[Fri Jul 30 12:11:36 2004]
Bit: 234759/234762, ERROR: ROUND OFF (0.5) > 0.40
Possible hardware failure, consult the readme file.
Continuing from last save file.

[Fri Jul 30 12:16:22 2004]
Bit: 234759/234762, ERROR: ROUND OFF (0.5) > 0.40
Possible hardware failure, consult the readme file.
Continuing from last save file.

Seems that the FFT length (12K) may be choosen too small in this case, since this machine never caused a "possible hardware failure" before.

Nevertheless it's very very fast and I haven't found any non-matching residuals so far. Great job, George!

-- Thomas
Thomas11 is offline  
Old 2004-07-30, 15:58   #8
ltd
 
ltd's Avatar
 
Apr 2003

22×193 Posts
Default

Newest Test report.

1. I have run 140 double checks for PSP number with a FFT of 16K.
All residues are OK.

2. I have run 6 tests with FFT 96K. All tests are OK also.

3. At the moment i run the PSP k/n pairs that have been found prime.
The first 6 test are OK. For the rest i will report later.

The new software is real fast and i recognized no bugs so far.

Lars
ltd is offline  
Old 2004-07-30, 20:27   #9
ltd
 
ltd's Avatar
 
Apr 2003

22·193 Posts
Default

All 11 PSP primes are also found with prp3.exe.
I had no crashes and no other errors yet.

If you want me to test something special let me know.

Lars
ltd is offline  
Old 2004-07-31, 03:23   #10
Prime95
P90 years forever!
 
Prime95's Avatar
 
Aug 2002
Yeehaw, FL

2·3·7·167 Posts
Default

Quote:
Originally Posted by Thomas11
The second one is a bit serious. I'm getting a ROUND OFF error while testing 3*2^234760-1:

Thanks for discovering this one. It is very troublesome. I recommend not using the new prp3 until I can figure out what is causing this.
Prime95 is online now  
Old 2004-07-31, 17:34   #11
Prime95
P90 years forever!
 
Prime95's Avatar
 
Aug 2002
Yeehaw, FL

11011011001102 Posts
Default

Further study of this naughty case reveals no problem in the FFT code. Unfortunately, the FFT data number being squared does not exhibit "random" properties that generates low round-off errors.

I'm talking to the PFGW folks about possible workarounds. They have seen this many times in the past. Since prp3 does the last 50 squarings with round-off checking enabled, then I think it is safe to use. If you get this error in the last few iterations, I'll bet you have a probable prime and the next rev of prp3 will backtrack and handle properly.
Prime95 is online now  
 

Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
LLR beta Version 3.8.13 (deprecated) Jean Penné Software 111 2015-01-26 21:41
Prime95 beta version 28.4 Prime95 Software 20 2014-03-02 02:51
Prime95 beta version 28.3 Prime95 Software 68 2014-02-23 05:42
Beta version 24.12 available Prime95 Software 33 2005-06-14 13:19
Early Beta of version 24.11 Prime95 Software 113 2005-05-24 17:05

All times are UTC. The time now is 15:12.

Sat Aug 8 15:12:42 UTC 2020 up 22 days, 10:59, 2 users, load averages: 2.18, 2.22, 2.18

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, 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.