LLR vs PFGW speed

Lennart · 2014-06-10, 16:48

What do you have this et to ? usellroverpfgw=

Most of my computer stared using pfgw.

Lennart

gd_barnes · 2014-06-10, 19:04

Quote:

Originally Posted by Lennart

What do you have this et to ? usellroverpfgw=

Most of my computer stared using pfgw.

Lennart

It is set to nothing, i.e. simply usellroverpfgw= . So the clients will use PFGW over LLR if it is available. All CRUS/NPLB servers are set this way by default.

Lennart · 2014-06-10, 19:29

Quote:

Originally Posted by gd_barnes

Excellent! I'll go ahead and add all of Riesel base 6 for n=1.5M-2M shortly.

It is set to nothing, i.e. simply usellroverpfgw= . So the clients will use PFGW over LLR if it is available. All CRUS/NPLB servers are set this way by default.

Change that or it takes much more time to test the numbers.

Lennart

gd_barnes · 2014-06-10, 19:36

Quote:

Originally Posted by Lennart

Change that or it takes much more time to test the numbers.

Lennart

Hummmm...I thought they used the same program/GWNUM libraries. Maybe this is machine and/or size specific. I'll go ahead and change it and see if there are comments from others about it.

Lennart · 2014-06-10, 19:42

Quote:

Originally Posted by gd_barnes

Hummmm...I thought they used the same program/GWNUM libraries. Maybe this is machine and/or size specific. I'll go ahead and change it and see if there are comments from others about it.

I can't say why but on my faster computer pfgw takes about 50%-100% more time. Could be some memorything also

Lennart

rogue · 2014-06-10, 20:21

There are various reasons the pfgw is slower. I haven't taken the time to investigate the reasons for it. I suspect that it has something to do with data conversions in the code between calls to the gwnum library. The sourcecode for pfgw is an absolute beast. The original developers tried to make it as C++ pure as possible so a lot of things are done in very abstract ways, which really hurts performance in some areas. I would love to rewrite it, but I have so little time and it would be an immense project that would require a lot of redesign.

mdettweiler · 2014-06-11, 00:55

Quote:

Originally Posted by Lennart

I can't say why but on my faster computer pfgw takes about 50%-100% more time. Could be some memorything also

Quote:

Originally Posted by rogue

There are various reasons the pfgw is slower. I haven't taken the time to investigate the reasons for it. I suspect that it has something to do with data conversions in the code between calls to the gwnum library. The sourcecode for pfgw is an absolute beast. The original developers tried to make it as C++ pure as possible so a lot of things are done in very abstract ways, which really hurts performance in some areas. I would love to rewrite it, but I have so little time and it would be an immense project that would require a lot of redesign.

Wow, I didn't know about this...I haven't really been paying close attention to my various computers' timings lately, but that might help explain why my Core2Duo (running LLR, because it was having trouble with PFGW earlier...not sure why, it's a wonky system anyway) has been faster than my Phenom II laptop (running PFGW), which is a few years newer. I had just assumed it was due to having more L2 cache, but maybe there's more to it than that.

Is this just a base 6 thing, or has it been observed on other bases too? Or, is it only a big factor on newer CPUs/newer gwnums? (If this has been around for a while, I'm surprised it hasn't been as well-known...again, I haven't been paying too close attention the last year so maybe this is old news and I just didn't get the memo.

)

gd_barnes · 2014-06-11, 04:38

Can someone please direct me to the latest Windows and Linux versions of LLR? I want to test the difference between PFGW and LLR myself on some of my old(ish) machines.

mdettweiler · 2014-06-11, 05:16

LLR downloads are here: http://jpenne.free.fr/index2.html

That reminds me, I need to upgrade...

MyDogBuster · 2014-06-11, 07:15

The differences between PFGW and LLR could be that LLR uses AVX, the new and improved instruction set from Intel. I've used it for about 2 years now.

It only works on Sandy Bridge and Ivy Bridge CPU's.

gd_barnes · 2014-06-11, 07:19

I'm getting from 10% to 50% speedup on my various machines by using the latest version of LLR vs. PFGW; both Windows and Linux. It's mostly in the 10-20% range on my Intel machines. A 40-50% speedup was noticed on a couple of my oldest AMD machines on large tests for a non-power-of-2 base. The speedup appears both machine and size dependent. There is less speedup on smaller tests.

I've now changed all of my private PRPnet servers to use LLR instead of PFGW. Port 1400 is the only public PRPnet server for NPLB/CRUS doing non-power-of-2 bases and it was changed earlier.

Because there is little speedup on small tests, I will still use PFGW for conjecture searches at low n-ranges because I like the Windows GUI and the scripting that is available.

Thank you for the suggestion Lennart!

2014-06-10, 16:48	#1
Lennart "Lennart" Jun 2007 2⁵×5×7 Posts	LLR vs PFGW speed What do you have this et to ? usellroverpfgw= Most of my computer stared using pfgw. Lennart

2014-06-11, 04:38	#8
gd_barnes May 2007 Kansas; USA 101·103 Posts	Can someone please direct me to the latest Windows and Linux versions of LLR? I want to test the difference between PFGW and LLR myself on some of my old(ish) machines. Last fiddled with by gd_barnes on 2014-06-11 at 20:03 Reason: remove base 6 comments

2014-06-11, 07:15	#10
MyDogBuster May 2008 Wilmington, DE 2²×23×31 Posts	The differences between PFGW and LLR could be that LLR uses AVX, the new and improved instruction set from Intel. I've used it for about 2 years now. It only works on Sandy Bridge and Ivy Bridge CPU's. Last fiddled with by MyDogBuster on 2014-06-11 at 07:17

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2014-06-10, 20:21	#6
rogue "Mark" Apr 2003 Between here and the 2⁴·397 Posts	There are various reasons the pfgw is slower. I haven't taken the time to investigate the reasons for it. I suspect that it has something to do with data conversions in the code between calls to the gwnum library. The sourcecode for pfgw is an absolute beast. The original developers tried to make it as C++ pure as possible so a lot of things are done in very abstract ways, which really hurts performance in some areas. I would love to rewrite it, but I have so little time and it would be an immense project that would require a lot of redesign.

2014-06-11, 05:16	#9
mdettweiler A Sunny Moo Aug 2007 USA (GMT-5) 3×2,083 Posts	LLR downloads are here: http://jpenne.free.fr/index2.html That reminds me, I need to upgrade...

2014-06-11, 07:19	#11
gd_barnes May 2007 Kansas; USA 101×103 Posts	I'm getting from 10% to 50% speedup on my various machines by using the latest version of LLR vs. PFGW; both Windows and Linux. It's mostly in the 10-20% range on my Intel machines. A 40-50% speedup was noticed on a couple of my oldest AMD machines on large tests for a non-power-of-2 base. The speedup appears both machine and size dependent. There is less speedup on smaller tests. I've now changed all of my private PRPnet servers to use LLR instead of PFGW. Port 1400 is the only public PRPnet server for NPLB/CRUS doing non-power-of-2 bases and it was changed earlier. Because there is little speedup on small tests, I will still use PFGW for conjecture searches at low n-ranges because I like the Windows GUI and the scripting that is available. Thank you for the suggestion Lennart!