20130708, 18:28  #12 
"Curtis"
Feb 2005
Riverside, CA
11715_{8} Posts 
5 days on a 460M for Lorgix' second C157 has produced no strong polys. Here's the best, with msieve suggesting 2.01 to 2.31 as the expected range:
Code:
# norm 2.916149e015 alpha 7.119644 e 1.883e012 rroots 5 skew: 1639936.64 c0: 8532868550138516311046827336336400640 c1: 70998128199694820805749331912482 c2: 52696319235656576134337513 c3: 75162003432935559781 c4: 19930163724423 c5: 8036784 Y0: 860303108391035434159057424509 Y1: 44662544129823973 
20130708, 18:35  #13 
Sep 2010
Scandinavia
3×5×41 Posts 
Thanks for the polynomials! I haven't gotten around to poly selection on GPU yet, so this saves days of CPUtime.
Hopefully someone will improve on the second one. You seem to know your way around the parameters, so I guess this is what's called 'bad luck'. I might get a used GTX560Ti or something like that (ideas?) so that I have some GPUpower to experiment with. 
20130708, 18:49  #14 
"Curtis"
Feb 2005
Riverside, CA
37×137 Posts 
You're quite welcome. Now that I know you don't have a GPU, I volunteer to find you at least decent polys for the next few months of your factoring. They may not hit msieve's GPUtarget range every time, but doing your poly selects beats LLRcuda as a good use of my GPU.
Repeated searches in the C155+ region give me some incentive to learn how to testsieve, which leads to fiddling with the knobs as Jason puts it. All useful knowledge, and possibly heading for a beginnerguide midlevel GNFS entry. GPU ideas: Go cheap, just get anything that supports the right flavor of CUDA. Even a lowend current card will be 50100x faster for stage 1, while using fewer watts than a $100+ card. Last fiddled with by VBCurtis on 20130708 at 18:51 Reason: GPU opinion 
20130708, 18:55  #15 
"Vincent"
Apr 2010
Over the rainbow
2×3^{2}×149 Posts 
The GTX5xx are 2 generation behind. It might be hard to get "new" one. I guess a GTX 650 or 640 (if they are not only for laptop) might work for you.

20130708, 19:31  #16  
Sep 2010
Scandinavia
267_{16} Posts 
Quote:
There are currently five p^q1GNFScandidates in the range 154156. I could pretest some above 160 as well. I also have my eyes on a HPnumber in the low 160s. So there's no shortage of candidates, if you're up for it. I really should be getting a new GPU some time soon (in a few moths, at least). More powerful ones should be very useful for ECM. Does poly select saturate any GPU? (can it use any number of cores?) Maybe I'll opt for a cheaper one; a GT630 based on GK208 (meaning 28nm) was released fairly recently. Should I look for the latest Compute Capability? (I don't really know the significance of that) Quote:
The GTX650 should be close to peak performance/$ (in the sense of MHz*cores/$), in the 600series, and so should be a good choice I suppose. The 6 & 700series use an entirely different architecture than the 4 & 500, so I don't really know how to compare them. Specifically I'd like to know what correction factor I need in order to compare MHz*cores between Fermi and Kepler. In terms of poly select performance (and ECM performance). 

20130708, 19:38  #17 
"Vincent"
Apr 2010
Over the rainbow
2·3^{2}·149 Posts 
VBcurtis, what msieve version did you use to find that poly? it seems that Msieve150 and below surevaluate the poly score a bit.

20130708, 20:55  #18 
"Curtis"
Feb 2005
Riverside, CA
37·137 Posts 
1.51, svn 845 (I think). April 2013 download, premade binary. It should be the newer/lower Evalues.
My GPU also drives my main screen, and the only time response has slowed was on the C210 sextic search. I've run cudaLLR for 12 months straight, and now poly select, with no apparent effect on the screen. I suggest you get CUDA drivers installed and test things out if nothing else, you can see how many hits you get overnight on the card. My mobileGPU part isn't all that fast, and still can produce 8 hrs' worth of nps work in just an hour or two. So, just overnight GPU np1 runs might produce more than enough data for stage 2 needs. Yes, I am game for at least a halfdozen candidates after those already posted by you and Chris. Last fiddled with by VBCurtis on 20130708 at 21:00 Reason: GPU commentary 
20130709, 02:10  #19 
"Vincent"
Apr 2010
Over the rainbow
2·3^{2}·149 Posts 
For now I have one *good* hit , score is equivalent to VBCurtis but skew is a bit lower
Code:
Tue Jul 09 02:19:43 2013 factoring 3787388118933512063249259173231597770049112435945032094640277541632460519045009491164974276597271170346757143570242916437315466248541421375702840232794402591 (157 digits) Tue Jul 09 02:37:40 2013 R0: 1063466059487867106617472794654 Tue Jul 09 02:37:40 2013 R1: 64668823176851 Tue Jul 09 02:37:40 2013 A0: 3962907102148251811365883799925121155 Tue Jul 09 02:37:40 2013 A1: 989212107945990307577657150068 Tue Jul 09 02:37:40 2013 A2: 6390045909351316737980130 Tue Jul 09 02:37:40 2013 A3: 9592336224573633921 Tue Jul 09 02:37:40 2013 A4: 5859137926178 Tue Jul 09 02:37:40 2013 A5: 2784336 Tue Jul 09 02:37:40 2013 skew 1408059.13, size 2.287e015, alpha 6.085, combined = 1.833e012 rroots = 3 Last fiddled with by firejuggler on 20130709 at 02:10 
20130709, 02:14  #20 
I moo ablest echo power!
May 2013
3×5×7×17 Posts 
For the 1st C155 listed, this is the best I've gotten thus far. It's a bit below the expected range, but not by too much:
Code:
expecting poly E from 2.62e012 to > 3.02e012 R0: 1982277912715175423679197808784 R1: 69837075648803257 A0: 44322257284138334787861242542456972633815 A1: 9286106559194619360096878548752378 A2: 108520072080442627462348267 A3: 10202649139317912268 A4: 61572653402 A5: 1740 skew 45960569.14, size 4.023e015, alpha 7.466, combined = 2.541e012 rroots = 5 
20130709, 06:34  #21 
"Vincent"
Apr 2010
Over the rainbow
2·3^{2}·149 Posts 
Code:
factoring 3787388118933512063249259173231597770049112435945032094640277541632460519045009491164974276597271170346757143570242916437315466248541421375702840232794402591 (157 digits) R0: 1378574698621825663558022013546 R1: 214052541470369 A0: 175040708004969558266567903993405593325 A1: 220312394373520757850174317763772 A2: 49282988466830844032614321 A3: 25532977516064005444 A4: 3884830113524 A5: 760656 skew 3526801.51, size 2.601e015, alpha 7.664, combined = 1.978e012 rroots = 3 Last fiddled with by firejuggler on 20130709 at 06:47 
20130713, 17:19  #22 
"Curtis"
Feb 2005
Riverside, CA
37·137 Posts 
Here is the poly for 39^158+1:
Code:
# norm 5.644615e015 alpha 7.931357 e 2.775e012 rroots 3 skew: 1813413.83 c0: 26576343119721934097475724487682275175 c1: 58618135712883968651879051388681 c2: 21402685978619238283492841 c3: 24030041819615310289 c4: 13579142843224 c5: 4598160 Y0: 415948918490177005559476926358 Y1: 30809158838486467 Edit: Ah, seems post 121 refers to this third number. I'll stop my search now, run npr on the overnight data, and report if I found a better poly. Edit2: Nothing of use. I am now working on the 3rd number from post #85. Firejuggler, the 4th number from post 85 has had no work yet. Last fiddled with by VBCurtis on 20130713 at 17:52 
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