Is there any chance of implementing the "Wagstaff" form (2^p+1)/3? It would only require a tweaked modular reduction -- or is there a 64 bit LLR on its way? :smile:

[QUOTE=rogue;275804]The speed increase appears to be dependent upon the values of k and b and the CPU the software is run on. Some combinations will see more than a 30% increase in speed. Even for base 2, pfgw64 is faster than LLR on my laptop.[/QUOTE]

I am finding the opposite. My version of LLR is currently outperforming PFGW on the numbers I am testing, but I am using base 10 and not base 2.

[QUOTE=SaneMur;276310]I am finding the opposite. My version of LLR is currently outperforming PFGW on the numbers I am testing, but I am using base 10 and not base 2.[/QUOTE]

Are you referring the 64-bit pfgw or 32-bit pfgw?

In some rare occations (for non-base-2 tests) I found that pfgw switches somewhat earlier to a higher FFT length, while LLR stays at the lower FFT length.

I thought that both are using the same routines from gwnums (e.g. gwinfo() ) for determining the proper FFT lengths. But maybe I'm missing something and the algorithms used by both programs are not directly comparable...

[QUOTE=rogue;276311]Are you referring the 64-bit pfgw or 32-bit pfgw?[/QUOTE]

I was using the 64-bit version of pfgw.

[QUOTE=Thomas11;276331]In some rare occations (for non-base-2 tests) I found that pfgw switches somewhat earlier to a higher FFT length, while LLR stays at the lower FFT length.

I thought that both are using the same routines from gwnums (e.g. gwinfo() ) for determining the proper FFT lengths. But maybe I'm missing something and the algorithms used by both programs are not directly comparable...[/QUOTE]

I actually found a prime that the current version of LLR cannot solve. It gets roundoff errors on every machine I try, but PFGW is able to prove it is prime.

The "development version" of LLR, however, can solve it, after resizing the FFT after the first attempt does not work.

llrAVX
 

From [URL="http://www.primegrid.com/forum_thread.php?id=3912&nowrap=true#46393"]here[/URL].

[quote]
[B][URL="http://www.primegrid.com/show_user.php?userid=52890"]Gary Craig[/URL][/B], a member of [B][URL="http://www.primegrid.com/team_display.php?teamid=2280"]Aggie The Pew[/URL][/B], was successful in compiling an AVX version of LLR using [B]gwnum v27.2[/B] ([URL]ftp://mersenne.org/gimps/source272.zip[/URL]) and [B][URL="http://jpenne.free.fr/Development/llr386devsrc.zip"]LLR v3.8.6dev[/URL][/B]. We've been testing it for the past week with success. Depending on the LLR project, speed improvements range from 20% to 50%.

[COLOR=red][B]Currently, this can only be run using an app_info file and only available for [U]Linux 64[/U] and [U]MacIntel[/U] (untested) (we'll gladly accept other builds).[/B][/COLOR] A CPU only app_info file is included in the download that will allow you to participate in the following LLR projects:
[LIST][*]321 Prime Search[*]Cullen Prime Search[*]Prime Sierpinski Problem[*]Proth Prime Search[*]Seventeen or Bust[*]Sophie Germain Prime Search[*]The Riesel Problem[*]Woodall Prime Search[/LIST]Before using app_info, please be sure to have all previous work completed and returned. Otherwise, all work will be lost. If someone would like to provide step by step instructions, I'll be happy to include them in this post. Additionally, if anyone wishes to create a full project app_info file (including GPU), that can be included in the package as well. Ronald has app_info files on his [B][URL="http://primegrid.pytalhost.net/"]site[/URL][/B] which can be modified to use with llrAVX.

Download llrAVX with app_info here: [B][URL="http://www.primegrid.com/download/llr3.8.6dev_avx.7z"]llr3.8.6dev_avx.7z[/URL][/B]

This has been tested on Sandy Bridge but should also work on Bulldozer.
[/quote]

I just completed a succesfull Sierpinski base 58 test with a 38 % speed bost, using Prime95 version 27.2 compared to LLR version 3.8.5, both versions running on Windows 7 64bit on a Sandy Bridge K2500 2.8 GHz, no overclocking done. Both LLR with older thoroughly tested version of GWnum library aswell as Prime95 v. 27.2, produced the same residual, only Prime95 used 6 minutes and 16.75 seconds while LLR used 10 minues and 9.455 seconds. This succesfull testing aswell as primegrid reports of no problem using the new AVX FFTs, has convinced me to use Prime95, to complete the remainder of my S58 tests.

Thanks for the hard work George. If anyone explodes and gets annoyed of me mentioning my equipment, please feel free to edit that part out. No offence if you do :smile:

Take care

Kenneth

People over there [url=http://www.primegrid.com/forum_thread.php?id=3933]are reporting problems[/url] with the AVX build on AMD Bulldozer-based processors. Any such problems over here with 27.2?

I think the main issue is people running this new version without comparing residues from previous stable client but I am not the one who will be doing double checks so I don't care.

This problem has nothing to do with DC...
I compiled llr386 and llr386dev against the gwnum27.2 and get problems also with my Core2-cpu's. [quote]After seeing some invalid SGS-results in the stats for my [url=http://www.primegrid.com/results.php?hostid=115188&offset=0&show_names=0&state=4&appid=2]host 115188[/url], i started one on the bash and got the message: [quote]./[b]sllr3.8.6-linux32_avx[/b] -d -q"30448908048555*2^666666-1"
Starting Lucas Lehmer Riesel prime test of 30448908048555*2^666666-1
Using zero-padded Core2 type-1 FFT length 72K, Pass1=96, Pass2=768
Iter: 6/45, ERROR: ROUND OFF (1) > 0.4
Continuing from last save file.
Disregard last error. Result is reproducible and thus not a hardware problem.
For added safety, redoing iteration using a slower, more reliable method.
Continuing from last save file.
Iter: 6/45, ERROR: ROUND OFF (1) > 0.4
Continuing from last save file.
Unrecoverable error, Restarting with next larger FFT length...
Starting Lucas Lehmer Riesel prime test of 30448908048555*2^666666-1
Using zero-padded Core2 type-3 FFT length 80K, Pass1=320, Pass2=256
Iter: 5/45, ERROR: ROUND OFF (1) > 0.4
Continuing from last save file.
Iter: 3/45, ERROR: ROUND OFF (1) > 0.4
Continuing from last save file.
Iter: 4/45, ERROR: ROUND OFF (1) > 0.4
Continuing from last save file.
Disregard last error. Result is reproducible and thus not a hardware problem.
For added safety, redoing iteration using a slower, more reliable method.
Continuing from last save file.
[b]Fatal error at setup : Number sent to gwsetup is too large for the FFTs to handle.[/b]
[/quote]

I get the same message also with: [quote]./[b]sllr3.8.6[u]dev[/u]-linux32_avx[/b] -d -q"30448908048555*2^666666-1"
Starting Lucas Lehmer Riesel prime test of 30448908048555*2^666666-1
Using zero-padded Core2 type-1 FFT length 72K, Pass1=96, Pass2=768
Iter: 6/45, ERROR: ROUND OFF (1) > 0.4
Continuing from last save file.
Disregard last error. Result is reproducible and thus not a hardware problem.
For added safety, redoing iteration using a slower, more reliable method.
Continuing from last save file.
Iter: 6/45, ERROR: ROUND OFF (1) > 0.4
Continuing from last save file.
Unrecoverable error, Restarting with next larger FFT length...
Starting Lucas Lehmer Riesel prime test of 30448908048555*2^666666-1
Using zero-padded Core2 type-3 FFT length 80K, Pass1=320, Pass2=256
Iter: 6/45, ERROR: ROUND OFF (1) > 0.4
Continuing from last save file.
Unrecoverable error, Restarting with next larger FFT length...
Starting Lucas Lehmer Riesel prime test of 30448908048555*2^666666-1
Using zero-padded Core2 type-1 FFT length 84K, Pass1=112, Pass2=768
Iter: 6/45, ERROR: ROUND OFF (1) > 0.4
Continuing from last save file.
Unrecoverable error, Restarting with next larger FFT length...
Starting Lucas Lehmer Riesel prime test of 30448908048555*2^666666-1
Using zero-padded Core2 type-3 FFT length 96K, Pass1=128, Pass2=768
Iter: 6/45, ERROR: ROUND OFF (1) > 0.4
Continuing from last save file.
Unrecoverable error, Restarting with next larger FFT length...
Starting Lucas Lehmer Riesel prime test of 30448908048555*2^666666-1
Using zero-padded Core2 type-3 FFT length 112K, Pass1=448, Pass2=256
Iter: 5/45, ERROR: ROUND OFF (1) > 0.4
Continuing from last save file.
Iter: 5/45, ERROR: ROUND OFF (1) > 0.4
Continuing from last save file.
Unrecoverable error, Restarting with next larger FFT length...
[b]Fatal error at setup : Number sent to gwsetup is too large for the FFTs to handle.[/b][/quote]

...and: [quote]./[b]sllr3.8.6[u]dev[/u]-linux64_avx[/b] -d -q"30448908048555*2^666666-1"
Starting Lucas Lehmer Riesel prime test of 30448908048555*2^666666-1
Using zero-padded Core2 type-1 FFT length 72K, Pass1=96, Pass2=768
Iter: 6/45, ERROR: ROUND OFF (1) > 0.4
Continuing from last save file.
Disregard last error. Result is reproducible and thus not a hardware problem.
For added safety, redoing iteration using a slower, more reliable method.
Continuing from last save file.
Iter: 6/45, ERROR: ROUND OFF (1) > 0.4
Continuing from last save file.
Unrecoverable error, Restarting with next larger FFT length...
Starting Lucas Lehmer Riesel prime test of 30448908048555*2^666666-1
Using zero-padded Core2 type-3 FFT length 80K, Pass1=320, Pass2=256
Iter: 6/45, ERROR: ROUND OFF (1) > 0.4
Continuing from last save file.
Unrecoverable error, Restarting with next larger FFT length...
Starting Lucas Lehmer Riesel prime test of 30448908048555*2^666666-1
Using zero-padded Core2 type-1 FFT length 84K, Pass1=112, Pass2=768
Iter: 6/45, ERROR: ROUND OFF (1) > 0.4
Continuing from last save file.
Unrecoverable error, Restarting with next larger FFT length...
Starting Lucas Lehmer Riesel prime test of 30448908048555*2^666666-1
Using zero-padded Core2 type-3 FFT length 96K, Pass1=128, Pass2=768
Iter: 6/45, ERROR: ROUND OFF (1) > 0.4
Continuing from last save file.
Unrecoverable error, Restarting with next larger FFT length...
Starting Lucas Lehmer Riesel prime test of 30448908048555*2^666666-1
Using zero-padded Core2 type-3 FFT length 112K, Pass1=448, Pass2=256
Iter: 5/45, ERROR: ROUND OFF (1) > 0.4
Continuing from last save file.
Iter: 5/45, ERROR: ROUND OFF (1) > 0.4
Continuing from last save file.
Unrecoverable error, Restarting with next larger FFT length...
[b]Fatal error at setup : Number sent to gwsetup is too large for the FFTs to handle.[/b]
[/quote]



[add]
I made a retest with the PG-app v6.10: [quote]./[b]primegrid_sllr_3.8.6_i686-pc-linux-gnu[/b] -d -q"30448908048555*2^666666-1"
Starting Lucas Lehmer Riesel prime test of 30448908048555*2^666666-1
Using zero-padded Core2 type-1 FFT length 72K, Pass1=96, Pass2=768
V1 = 5 ; Computing U0...done.Starting Lucas-Lehmer loop...
30448908048555*2^666666-1, iteration : 10000 / 666666 [1.50%]. Time per iteration : 1.292 ms.
448908048555*2^666666-1, iteration : 30000 / 666666 [4.50%]. Time per iteration : 1.245 ms.
^C
Caught signal. Terminating.[/quote][/quote]