Parameter explorations for CADO 165-170 digits

[bur]

Thanks, the c167 took 12 days of sieving, the c170 had enough relations already after 15 days, much faster than I anticipated also from c150 and c160 jobs on that machine.


Anyway, I tried again with 235M rels and 166.7M uniques which resulted in a matrix:

matrix is 10297670 x 10297895 (4105.4 MB) with weight 1089257460 (105.77/col)
sparse part has weight 973222523 (94.51/col)
linear algebra completed 309078 of 10297895 dimensions (3.0%, ETA 28h36m)

The size is ok, I think? If all will go fine for the rest this took a total of 180 core-days on an i9-10900k. About 15 core-days for polysearch (could have been less, I was just trying different parameters), 150 for sieving and 15 for LA.

I had anticipated something like 3-4 weeks WCT for this, now it only took 2.5 weeks.

[bur]

I am currently testing the optimal q-min for the c170, it seems it's quite large as well. The q-range of the original run was 15M-84M yielding 166.4M uniques. In the q-range 24M-93M I got 169.0M uniques.

I also have another c165 to factor, should I just use the same parameters as for the c167 discussed here before?

[firejuggler]

Are the parametters for polyselect of interest or only the sieving LA and the rest?

[firejuggler]

ok, I tried a polyselect on the same range, but with different tasks.polyselect.P. on a C165
(7^178*178^7-1)/129
with

tasks.polyselect.P = 300e3
tasks.polyselect.admin=1.99e6
tasks.polyselect.admax = 2e6
tasks.polyselect.adrange = 1e3
tasks.polyselect.incr = 250
tasks.polyselect.nq = 3125
tasks.polyselect.nrkeep = 6
tasks.polyselect.ropteffort=10
tasks.polyselect.sopteffort=200

tasks.polyselect.P=300e3

R0: -35809166954067912357846660220632
R1: 13463319667006865269
A0: -2219834428349037570991732730801168691845
A1: -692194239737244432596138760691083
A2: 488342217850668125365542693
A3: -31512898162007566885
A4: -45218104446796
A5: 1994500
skew 3796573.56, size 3.067e-016, alpha -6.046, combined = 5.428e-013 rroots = 3

with P=3e6

R0: -35750679366989574211105475195855
R1: 633662203321820819083499
A0: 82290745085368826347864212268994400888
A1: -78146700994698691661021326578602
A2: -288482486297396525055747957
A3: -4358229227643201247
A4: 5932124350875
A5: 17995500
skew 1393695.22, size 3.034e-016, alpha -6.080, combined = 5.528e-013 rroots = 3

and P=30e6

R0: -35809200555754954673312861203782
R1: 31581039660216687989269
A0: 11327319509762555016982123133746333048
A1: 286465213321329043975159328886322
A2: -306077442964448660296883751
A3: -265544123343226564667
A4: 1365778877333728
A5: -4564560000
skew 379204.77, size 1.848e-016, alpha -7.335, combined = 4.089e-013 rroots = 3

clearly the P=30e6 isn't good for that short range.

[VBCurtis]

Originally Posted by firejuggler

ok, I tried a polyselect on the same range, but with different tasks.polyselect.P. on a C165
(7^178*178^7-1)/129
with

tasks.polyselect.P = 300e3
tasks.polyselect.admin=1.99e6
tasks.polyselect.admax = 2e6
tasks.polyselect.adrange = 1e3
tasks.polyselect.incr = 250
tasks.polyselect.nq = 3125
tasks.polyselect.nrkeep = 6
tasks.polyselect.ropteffort=10
tasks.polyselect.sopteffort=200

tasks.polyselect.P=300e3

nq=3125 is highly unlikely to yield a good poly. Use 15625, or if you'd like to experiment 78125.
I'd turn sopteffort way down, too- something like 5 to 10 should be best for C160-170. Better to search over more a5 values than to look *really* hard at a few. Perhaps you chose these values because you wanted to compare various P values- but as it is poly select is such a needle-in-haystack game that using poly score as a measure of setting effectiveness is hazy, at best.
If you want to compare settings, I suggest you look at the lognorm score posted after stage 1; that's giving you a measure of the quality of the worst poly found before root-opt. It's possible that some settings yield better top polys but worse "worst" polys, but I haven't found such settings yet.

[charybdis]

incr=250 is not a good choice. Better values to try would be 60, 120, 210, 420; you want the leading coefficient to have lots of small prime factors.