Quote:
Originally Posted by bsquared
Sparing me the build process to figure it out for myself, does GWNUM provide a speedup even for "small" inputs like 2^1277-1? How about 2^941-1? Wondering where the cutoff is to normal mulmod methods.
(Small, of course, relative to where prime95 usually operates.)
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Attempting to get something useful out of this thread, here are some timings on a 2Ghz Skylake VM. Without GWNUM:
Code:
$ echo "2^1277-1" | ./ecm -c 5 11e6
GMP-ECM 7.0.4 [configured with GMP 6.2.0, --enable-asm-redc] [ECM]
Input number is 2^1277-1 (385 digits)
Using B1=11000000, B2=35133391030, polynomial Dickson(12), sigma=0:15382913345576557885
Step 1 took 63126ms
Step 2 took 28310ms
Run 2 out of 5:
Using B1=11000000, B2=35133391030, polynomial Dickson(12), sigma=0:2472923556820086104
Step 1 took 63697ms
Step 2 took 28330ms
Run 3 out of 5:
Using B1=11000000, B2=35133391030, polynomial Dickson(12), sigma=0:13772778279637613489
Step 1 took 63532ms
Step 2 took 28339ms
Run 4 out of 5:
Using B1=11000000, B2=35133391030, polynomial Dickson(12), sigma=0:4149983287909296098
Step 1 took 65040ms
Step 2 took 28394ms
Run 5 out of 5:
Using B1=11000000, B2=35133391030, polynomial Dickson(12), sigma=0:3089621796835281869
Step 1 took 65407ms
Step 2 took 28430ms
With GWNUM linked:
Code:
$ echo "2^1277-1" | ./ecm -c 5 11e6
GMP-ECM 7.0.4 [configured with GMP 6.2.0, GWNUM 29.8, --enable-asm-redc] [ECM]
Due to incompatible licenses, this binary file must not be distributed.
Input number is 2^1277-1 (385 digits)
Using B1=11000000, B2=35133391030, polynomial Dickson(12), sigma=0:1133017334638497343
Step 1 took 52939ms
Step 2 took 28574ms
Run 2 out of 5:
Using B1=11000000, B2=35133391030, polynomial Dickson(12), sigma=0:16936162798099609109
Step 1 took 52935ms
Step 2 took 28488ms
Run 3 out of 5:
Using B1=11000000, B2=35133391030, polynomial Dickson(12), sigma=0:4745769159583183902
Step 1 took 52719ms
Step 2 took 28706ms
Run 4 out of 5:
Using B1=11000000, B2=35133391030, polynomial Dickson(12), sigma=0:14575819613407288447
Step 1 took 52688ms
Step 2 took 28512ms
Run 5 out of 5:
Using B1=11000000, B2=35133391030, polynomial Dickson(12), sigma=0:7117923393329265041
Step 1 took 52795ms
Step 2 took 28585ms
So, a decent speedup in stage 1.