[QUOTE=xtreme2k;362798]Any advice to tweak my system for higher output?[/QUOTE]

According to [url]http://www.mersenne.ca/mfaktc.php?sort=ghdpd&noA=1[/url], you're right were you should be.

work in progress
 

Hello!
[LIST][*][B][U]mfaktc v0.20[/U][/B]: ./mfaktc.exe -tf 1000003 64 65
[CODE]mfaktc v0.20 (64bit built)
[...]
SievePrimes [B][COLOR="Red"]200000[/COLOR][/B]
[...]
got assignment: exp=1000003 bit_min=64 bit_max=65 (3.74 GHz-days)
WARNING: SievePrimes is too big for the current assignment, lowering to [B][COLOR="Red"]78497[/COLOR][/B]
It is not allowed to sieve primes which are equal or bigger than the
exponent itself!
[...]
Using GPU kernel "barrett76_mul32"
[...][/CODE][*][B][U]mfaktc v0.21-pre5[/U][/B]: ./mfaktc.exe -tf 1000003 64 65
[CODE]mfaktc v0.21-pre5 (64bit built)
[...]
SievePrimes [B][COLOR="Red"]200000[/COLOR][/B]
[...]
got assignment: exp=1000003 bit_min=64 bit_max=65 (3.74 GHz-days)
[...]
Using GPU kernel "barrett76_mul32"
[I]sieve_init_class(1000003, 9223344364080, 200000)
last prime in sieve: [B][COLOR="Red"]2750161[/COLOR][/B]
removing [B][COLOR="Red"]1000003[/COLOR][/B] from sieve
adding [B][COLOR="Red"]2750171[/COLOR][/B] to sieve[/I]
[...][/CODE]
The [I]italic[/I] part are temporary printfs() in the code, they will be remove in release version.
2750161 is the 200000th odd prime
1000003 is removed from the sieving process because factor candidates (FCs) are 2 * k * exp + 1 so they are always 1 mod <exp>.
2750171 is the 200001st odd prime which takes place for the removed prime.[*][B][U]mfaktc v0.21-pre5[/U][/B]: ./mfaktc.exe -tf [B][COLOR="Red"]100019[/COLOR][/B] 1 55
[CODE]mfaktc v0.21-pre5 (64bit built)
[...]
SievePrimes [B][COLOR="Red"]200000[/COLOR][/B]
[...]
got assignment: exp=100019 bit_min=1 bit_max=55 (0.05 GHz-days)
[...]
Using GPU kernel "71bit_mul24"
[I]sieve_init_class(100019, 0, 200000)
last prime in sieve: [B][COLOR="Red"]2750161[/COLOR][/B]
removing [B][COLOR="Red"]100019[/COLOR][/B] from sieve
removing [B][COLOR="Red"]1800343[/COLOR][/B] from sieve
adding [B][COLOR="Red"]2750171[/COLOR][/B] to sieve
adding [B][COLOR="Red"]2750177[/COLOR][/B] to sieve[/I]
[...][/CODE]
again 2750161 is the 200000th odd prime
100019 is removed because it is the exponent itself
1800343 is removed from the sieving process because it is a possible FC: 1800343 = 1 mod (2 * 100019). Removing it allows finding composite factors which contain 1800343. If we ignore composite factors an offset for the sieving would be enough.
2000381 is [B]not removed[/B] even it is prime and 2000381 = 1 mod (2 * 100019) but doesn't satisfy the [URL="http://mersenne.org/various/math.php"]mod 8 rule[/URL] so it isn't a FC and can be used for sieving.
2750171 and 2750177 are the 200001st and 200002nd odd primes which take place for the removed primes.[/LIST]
Oliver

Very interesting/nice. Do you also plan to add add files(worktodo.add) as well?

I am looking forward to its debut. :tu:

Would version 0.21 have any speed improvements over 0.20?

Hello!

[QUOTE=kracker;363144]Very interesting/nice. Do you also plan to add add files(worktodo.add) as well?[/QUOTE]

Yes, worktodo.add is planned.

[QUOTE=ixfd64;363159]Would version 0.21 have any speed improvements over 0.20?[/QUOTE]

Yes, for some bitranges if you are running mfaktc[LIST][*]on a CC 1.x GPU by reordering kernel priorities based on recent measurement on my GTX 275[*]on a CC 3.5 GPU for barrett_87/88/92 kernels using funnel shift (see [URL="http://www.mersenneforum.org/showpost.php?p=333722&postcount=2241"]this[/URL] and [URL="http://www.mersenneforum.org/showpost.php?p=334251&postcount=2243"]this[/URL] post)
Raw Kernel speeds on a Tesla K20:
[CODE]barrett87_mul32 368.01M/s (without funnel-shift 357.09M/s)
barrett88_mul32 367.45M/s (without funnel-shift 347.80M/s)
barrett92_mul32 306.60M/s (without funnel-shift 293.69M/s)[/CODE][/LIST]So only minor performance improvements in the next release, sorry!

Oliver

It's still a noticeable improvement, though. :smile:

work in progress
 

Happy new year to everyone!

[B]./mfaktc.exe -tf 66362159 68 69[/B]
[CODE]mfaktc v0.21-pre6 (64bit built)

[...]
GPU Sieving [B][COLOR="Red"]enabled[/COLOR][/B]
GPUSievePrimes 82486
GPUSieveSize 64Mi bits
GPUSieveProcessSize 16Ki bits
[...]
CUDA device info
name [B][COLOR="Red"]GeForce GTX 275[/COLOR][/B]
compute capability [B][COLOR="Red"]1[/COLOR][/B].3
[...]
clock rate 1404MHz
[...]
got assignment: exp=66362159 bit_min=68 bit_max=69 (0.90 GHz-days)
Starting trial factoring M66362159 from 2^68 to 2^69 (0.90 GHz-days)
[...]
Using GPU kernel "barrett76_mul32[B][COLOR="Red"]_gs[/COLOR][/B]"
Date Time | class Pct | time ETA | GHz-d/day Sieve Wait
Jan 02 15:31 | 0 0.1% | 1.272 20m20s | 63.74 82485 n.a.%
Jan 02 15:31 | 4 0.2% | 1.259 20m06s | 64.40 82485 n.a.%
Jan 02 15:31 | 9 0.3% | 1.260 20m06s | 64.35 82485 n.a.%
[...]
[/CODE]

Compared to the same GPU using [B]CPU[/B] (Core i7 9xx series @3.5GHz) sieving:
[CODE][...]
Using GPU kernel "barrett76_mul32"
[...]
Date Time | class Pct | time ETA | GHz-d/day Sieve Wait
Jan 02 15:35 | 24 0.6% | 1.232 19m35s | 65.81 25000 29.72%
Jan 02 15:35 | 25 0.7% | 1.207 19m10s | 67.17 28125 25.67%
Jan 02 15:35 | 37 0.8% | 1.197 19m00s | 67.73 31640 21.82%
Jan 02 15:35 | 40 0.9% | 1.186 18m48s | 68.36 35595 17.45%
Jan 02 15:35 | 45 1.0% | 1.175 18m36s | 69.00 40044 12.76%
Jan 02 15:35 | 49 1.1% | 1.165 18m26s | 69.59 45049 7.69%
Jan 02 15:35 | 52 1.2% | 1.154 18m14s | 70.26 50680 2.25%
Jan 02 15:35 | 60 1.4% | 1.154 18m13s | 70.26 50680 2.27%
Jan 02 15:35 | 61 1.5% | 1.154 18m12s | 70.26 50680 2.29%
[...]
[/CODE]

I've no clue what went wrong when I did the benchmarks prior release of mfaktc 0.20 and decided to disable GPU sieving on CC 1.x GPUs, performance was reproduceable horrible (less than half of the CPU sieve performance). I didn't do any changes (except the code which disables GPU sieving for old GPUs) related to GPU sieve.

Oliver

[QUOTE=TheJudger;363558]I've no clue what went wrong when I did the benchmarks prior release of mfaktc 0.20 and decided to disable GPU sieving on CC 1.x GPUs[/QUOTE]That's exciting (that GPU-sieving will be available for 1.x) --- I may have to plug my 8800GT back in :smile:

Now if you tell me that you've also enabled GPU sieving for <64-bit target, I'll jump for joy...

If you have AMD: [url]http://www.mersenneforum.org/showthread.php?p=363545#post363545[/url]

[QUOTE=flashjh;363586]If you have AMD: [url]http://www.mersenneforum.org/showthread.php?p=363545#post363545[/url][/QUOTE]Hmm... sounds promising... any chance of it getting ported to mfaktc?