mfakto: an OpenCL program for Mersenne prefactoring

[kriesel]

Originally Posted by axn

He's using standard Primenet conversion 1Gd/d = 2GFLOPS

Hmm, wouldn't that be based on Core2Duo instruction set and performance? By definition? https://www.mersenneforum.org/showpo...67&postcount=4

It might be considered standard, but it seems to me far from valid for application to a gpu with a completely different architecture and instruction set and its own performance constraints.

[axn]

Originally Posted by kriesel

It might be considered standard, but it seems to me far from valid for application to a gpu with a completely different architecture and instruction set and its own performance constraints.

As long as the algorithm used is same-ish (i.e. IBDWT), the architectural differences are irrelevant.

Given that the algorithm is same, 1 iteration at a given FFT size takes x floating point operations, snd will get you y GHzD credit. This won't change because of the processor. Only thing that is affected by the processor is the time to complete that iteration; the faster a processor completes an iteration, the higher its GHzD/d rating, but also its GFLOPS rating. But the conversion factor between these two doesn't change and will remain independent of the processor.

[kriesel]

Mfakto is performing TF, by a variety of kernels, not FFT multiplication by IBDWT.
FFT almost always uses DP. TF kernels may use SP or int. Different hardware designs have different ratios among them. Gpus have vastly different DP/SP or I think DP/int32 ratios than cpus.

[VBCurtis]

So what?
Each TF bit takes some specific amount of work. You're complaining about how we measure work done, but not suggesting some alternative.

[axn]

Originally Posted by kriesel

Mfakto is performing TF, by a variety of kernels, not FFT multiplication by IBDWT.
FFT almost always uses DP. TF kernels may use SP or int. Different hardware designs have different ratios among them. Gpus have vastly different DP/SP or I think DP/int32 ratios than cpus.

Well, whoops. I guess I don't remember the context of posts from two months ago that well :-(

All good points; you can inform OP to take those into consideration and adjust their calculations.

[DrobinsonPE]

GB-BRi5H-8250, i508250U, UHD 620, 16GB DDR-4, SSD, Windows 10.

mfakto 0.15pre7

C:\Users\user\mfakto\015pre7>mfakto -st

Selftest statistics
  number of tests           34026
  successful tests          33288
  no factor found           738

selftest FAILED!

I need to find what exponent levels it is failing on and see if there is just a range to avoid.

C:\Users\user\mfakto\015pre7>mfakto
mfakto 0.15pre7-MGW (64bit build)
OpenCL device info
  name                      Intel(R) UHD Graphics 620 (Intel(R) Corporation)
  device (driver) version   OpenCL 2.1 NEO  (27.20.100.8681)
  maximum threads per block 256
  maximum threads per grid  16777216
  number of multiprocessors 24 (24 compute elements)
  clock rate                1100 MHz
Automatic parameters
  threads per grid          0
  optimizing kernels for    INTEL
selftest PASSED!
got assignment: exp=115746439 bit_min=73 bit_max=74 (16.53 GHz-days)
Starting trial factoring M115746439 from 2^73 to 2^74 (16.53 GHz-days)
Using GPU kernel "cl_barrett32_76_gs_2"
Date    Time | class   Pct |   time     ETA | GHz-d/day    Sieve     Wait
Dec 20 08:18 |    0   0.1% | 60.505  16h07m |     24.58    81206    0.00%
Dec 20 08:19 |    5   0.2% | 60.985  16h13m |     24.39    81206    0.00%
Dec 20 08:20 |    9   0.3% | 61.054  16h13m |     24.36    81206    0.00%
Dec 20 08:21 |   12   0.4% | 61.219  16h15m |     24.30    81206    0.00%
Dec 20 08:22 |   17   0.5% | 61.204  16h14m |     24.30    81206    0.00%

[DrobinsonPE]

Originally Posted by DrobinsonPE

GB-BRi5H-8250, i508250U, UHD 620, 16GB DDR-4, SSD, Windows 10.

mfakto 0.15pre7

C:\Users\user\mfakto\015pre7>mfakto -st

Selftest statistics
  number of tests           34026
  successful tests          33288
  no factor found           738

selftest FAILED!

I need to find what exponent levels it is failing on and see if there is just a range to avoid.

All 738 -st errors are in the 61-62, 62-63, and 63-64 ranges.

[DrobinsonPE]

I5-4570T with HD4600 Graphics

mfakto 0.15pre7

C:\Users\user\mfakto>mfakto
mfakto 0.15pre7-MGW (64bit build)
Starting trial factoring M115801657 from 2^73 to 2^74 (16.52 GHz-days)
Using GPU kernel "cl_barrett32_76_gs_2"
Date    Time | class   Pct |   time     ETA | GHz-d/day    Sieve     Wait
Dec 22 06:48 |   12   0.4% | 89.923  23h52m |     16.53    81206    0.00%

[birtwistlecaleb]

Originally Posted by James Heinrich

Perhaps this one?
https://download.mersenne.ca/mfakto/mfakto-0.12-hd4000

edit: Although based on what Ken says below, you're likely fine with the normal latest-version (0.15-pre6):
https://download.mersenne.ca/mfakto/mfakto-0.15pre6

They both do not have a worktodo.txt, and it seems like they are broken because of that.

[James Heinrich]

Originally Posted by birtwistlecaleb

They both do not have a worktodo.txt, and it seems like they are broken because of that.

What do you mean? No program will come with worktodo.txt, that's what you supply with the assignments you're working on.
What error message(s) do you see when you run whichever version it is you're running?

[birtwistlecaleb]

Originally Posted by James Heinrich

What do you mean? No program will come with worktodo.txt, that's what you supply with the assignments you're working on.
What error message(s) do you see when you run whichever version it is you're running?

They both instantly close when they find that, so I can't see that. Am I supposed to manually add the file?