mersenneforum.org  

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

 
 
Thread Tools
Old 2004-08-02, 20:32   #12
Prime95
P90 years forever!
 
Prime95's Avatar
 
Aug 2002
Yeehaw, FL

1B6016 Posts
Default

I've uploaded a new prp3 that fixes a few minor bugs and avoids the problems with non-random data by doing special-but-slower multiplications for the last 25 iterations.

Let me know if you find any problems.
Prime95 is offline  
Old 2004-08-16, 09:30   #13
biwema
 
biwema's Avatar
 
Mar 2004

3·127 Posts
Default

I also downloaded and tested the new version of prp. For me, it is about 3 times faster! (19*2^531k+1; 32k FFT)
Congratulations, George!

Just one thing seems somewhat strange. (k*2^exp+1)
If I use k=19, I can go beyond exp=595000 and it still uses 32k FFT.
If I use K=10000 or so, it switches already below exp=447000 from 32K FFT to 48K FFT. with k=3 exponents upt to 638000 are possible with 32k FFT.

in the k*2^exp-1 we have more FFT lengths:
k=19 has 32kFFT up to 601000;
k=3 up to 645000 and k= 10000 up to 453000.
In the minus mode, more FFT sizes are available (28K and 40K instead of only 24K and 40K besides 32K).

Is that normal, that the threshholds of the fft sizes depend so greatly on the size of the k (mantissa)? If we use k=3 instead of 10000, the the difference is just 13 bits.
biwema is offline  
Old 2004-08-16, 13:47   #14
Prime95
P90 years forever!
 
Prime95's Avatar
 
Aug 2002
Yeehaw, FL

25×3×73 Posts
Default

This is all normal. In my modified-Percival IBDWT, log2(k)/2 bits are required in each FFT word.

So let's say the 32K FFT can handle 20 bits per FFT word. If k=1, n can be 32K*20 or 640K. If k = 8191, then log2(k)/2 = 6.5 bits. That leaves 13.5 bits per word. So now you can only handle n up to 32K*13.5 = 432K.
Prime95 is offline  
Old 2004-09-17, 02:32   #15
Prime95
P90 years forever!
 
Prime95's Avatar
 
Aug 2002
Yeehaw, FL

1B6016 Posts
Default

Warning: A bug has been uncovered for k values around 7 to 9 digits. A fix is underway.
Prime95 is offline  
Old 2004-09-17, 19:21   #16
Prime95
P90 years forever!
 
Prime95's Avatar
 
Aug 2002
Yeehaw, FL

11011011000002 Posts
Default

The fixed prp3 can now be downloaded.

You can get the versions from:

Windows: ftp://mersenne.org/gimps/prp3.zip
Linux: ftp://mersenne.org/gimps/prp3.tgz

The linux version is untested, I do not have Linux running on any P4s here.
Prime95 is offline  
 

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 05:42.

Tue Aug 4 05:42:38 UTC 2020 up 18 days, 1:29, 0 users, load averages: 1.38, 1.39, 1.30

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.