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Old 2021-08-26, 18:05   #30
kriesel's Avatar
Mar 2017
US midwest

132438 Posts

Originally Posted by clowns789 View Post
I factored 3321928171 to 91 bits with no factor. Anyone with a Radeon VII Pro who is willing to crunch a P-1 and PRP test is good to go!
Gpuowl would require extension to larger fft lengths, to attempt P-1 or PRP. Mihai has not posted a commit on GitHub for gpuowl since March 24. Amount of ram on GPUs we can afford is an issue; gpuowl at ~1Gbit Mersennes takes ~140 passes in P-1 stage 2 with 21 buffers, so ~3.32Gbit would be ~450 passes with ~6 buffers, on a 16GiB Radeon VII GPU or similar (Tesla P100).
2021-08-03 04:13:45 asr2/radeonvii2 990004423 P2(33M,990M) D=210, nBuf=21
2021-08-03 08:38:46 GpuOwl VERSION v7.2-53-ge27846f
2021-08-03 08:38:46 config: -user kriesel -cpu asr2/radeonvii2 -d 2 -maxAlloc 14G -proof 10 -use NO_ASM -autoverify 10 -block 1000 -autoverify 11
2021-08-03 08:38:46 device 2, unique id ''
2021-08-03 08:38:46 asr2/radeonvii2 990004423 FFT: 56M 4K:14:512 (16.86 bpw)
For -maxAlloc 15G nBuf=24 at 0.99G, stage 2 runtime ~10 days in v7.2-53 to unusually high bounds; probably ~4 days in v6.11-380. So for ~1 Gdigit, if Gpuowl were extended, ~ 1.5 - 4 months for P-1 stage 2 on a Radeon VII.

The alternative is Mlucas v20.0 with its new P-1 capability, which I'm looking into. Run times for P-1 would be even longer, perhaps 4-8 months on a Xeon Phi 7250.

Mlucas v20.0 or earlier does not have PRP proof generation yet. That's what Ernst plans to add next IIRC. PRP test run times would be very long (decades on my hardware).

Last fiddled with by kriesel on 2021-08-26 at 18:17
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