20200907, 11:28  #23 
"Mihai Preda"
Apr 2015
2×23×29 Posts 
Interesting. It looks as if that file was not written correctly, or corrupted on disk. When trying to use it for proof generation, the checksum mismatch was discovered. On restart, it tries first the proof power requested (8), and if that doesn't work, tries every power from higest to lowest to see if any is feasible given the residues that are present. This order is indeed not minimal (e.g. 8 is checked twice) but it represents an exceptional case so it's not worth "fixing" IMO.

20200907, 23:26  #24  
Random Account
Aug 2009
U.S.A.
7^{2}×37 Posts 
@preda:
Quote:
Quote:


20200908, 00:04  #25  
"Mihai Preda"
Apr 2015
10100110110_{2} Posts 
Quote:


20200908, 00:43  #26  
Random Account
Aug 2009
U.S.A.
715_{16} Posts 
Quote:
Edit: The proof is here: https://www.adrive.com/public/9Uj3T4/104968978.proof Last fiddled with by storm5510 on 20200908 at 00:51 

20200908, 01:42  #27 
"TF79LL86GIMPS96gpu17"
Mar 2017
US midwest
11363_{8} Posts 
Improving fallback to lower proof power etc.
This was a power 8 proof PRP run on Radeon 5700XT and Windows 10 that went awry. Aside from the reported checksum error, I see a few additional issues with this run sequence.
Code:
20200907 11:48:16 asr2/5700xt 99356317 OK 98400000 99.04%; 2212 us/it; ETA 0d 00:35; ed3540b5aa993e56 (check 1.11s) 20200907 11:55:39 asr2/5700xt 99356317 OK 98600000 99.24%; 2213 us/it; ETA 0d 00:28; 4569ca1b42f97bf5 (check 1.11s) 20200907 12:03:03 asr2/5700xt 99356317 OK 98800000 99.44%; 2212 us/it; ETA 0d 00:21; 52d0f07278cb3ea0 (check 1.10s) 20200907 12:10:27 asr2/5700xt 99356317 OK 99000000 99.64%; 2213 us/it; ETA 0d 00:13; 214b5e72adcb0097 (check 1.10s) 20200907 12:17:50 asr2/5700xt 99356317 OK 99200000 99.84%; 2212 us/it; ETA 0d 00:06; 8dc4afa02db98b6e (check 1.10s) 20200907 12:23:36 asr2/5700xt CC 99356317 / 99356317, af767eb4030a____ 20200907 12:23:38 asr2/5700xt 99356317 OK 99356800 100.00%; 2215 us/it; ETA 0d 00:00; 5a424b4dc57d3ccf (check 1.07s) 20200907 12:23:39 asr2/5700xt proof: building level 1, hash dc19c1ed5074bfed 20200907 12:23:39 asr2/5700xt proof: building level 2, hash e1c39c39ef8fec8c20200907 12:23:40 asr2/5700xt proof: building level 3, hash 4dff4687239f51cc 20200907 12:23:42 asr2/5700xt proof: building level 4, hash 7803518131602fc6 20200907 12:23:45 asr2/5700xt proof: building level 5, hash e6e93fce0591589a 20200907 12:23:51 asr2/5700xt proof: building level 6, hash 486bd862e2a3633f 20200907 12:23:53 asr2/5700xt checksum 78d6fc30 (expected 9be1d4ca) in '.\99356317\proof\23286660' 20200907 12:23:53 asr2/5700xt Exception NSt10filesystem7__cxx1116filesystem_errorE: filesystem error: checksum mismatch: No error 20200907 12:23:53 asr2/5700xt Bye >gpuowlwin 20200907 17:44:04 gpuowl v6.11364g36f4e2a 20200907 17:44:04 config: user kriesel cpu asr2/5700xt d 2 use NO_ASM maxAlloc 7500 20200907 17:44:04 device 2, unique id '' 20200907 17:44:04 asr2/5700xt 99356317 FFT: 5.50M 1K:11:256 (17.23 bpw) 20200907 17:44:04 asr2/5700xt Expected maximum carry32: 293D0000 20200907 17:44:05 asr2/5700xt OpenCL args "DEXP=99356317u DWIDTH=1024u DSMALL_HEIGHT=256u DMIDDLE=11u DPM1=0 DAMDGPU=1 DWEIGHT_STEP_MINUS_1=0xb.52db15a632b98p4 DIWEIGHT_STEP_MINUS_1=0xd.42fc054606498p5 DNO_ASM=1 clunsafemathoptimizations clstd=CL2.0 clfinitemathonly " 20200907 17:44:13 asr2/5700xt OpenCL compilation in 8.11 s 20200907 17:44:15 asr2/5700xt 99356317 OK 99200000 loaded: blockSize 400, 8dc4afa02db98b6e 20200907 17:44:15 asr2/5700xt validating proof residues for power 8 20200907 17:44:22 asr2/5700xt checksum 78d6fc30 (expected 9be1d4ca) in '.\99356317\proof\23286660' 20200907 17:44:22 asr2/5700xt validating proof residues for power 9 20200907 17:44:22 asr2/5700xt Can't open '.\99356317\proof\194056' (mode 'rb') 20200907 17:44:22 asr2/5700xt validating proof residues for power 8 20200907 17:44:27 asr2/5700xt checksum 78d6fc30 (expected 9be1d4ca) in '.\99356317\proof\23286660' 20200907 17:44:27 asr2/5700xt validating proof residues for power 7 20200907 17:44:30 asr2/5700xt checksum 78d6fc30 (expected 9be1d4ca) in '.\99356317\proof\23286660' 20200907 17:44:30 asr2/5700xt validating proof residues for power 6 20200907 17:44:30 asr2/5700xt Can't open '.\99356317\proof\1552443' (mode 'rb') 20200907 17:44:30 asr2/5700xt Proof disabled because of missing checkpoints 20200907 17:44:33 asr2/5700xt 99356317 OK 99200800 99.84%; 2199 us/it; ETA 0d 00:06; 924e6946b4f9fde2 (check 1.37s) 20200907 17:50:17 asr2/5700xt CC 99356317 / 99356317, af767eb4030a5338 20200907 17:50:18 asr2/5700xt 99356317 OK 99356400 100.00%; 2212 us/it; ETA 0d 00:00; abffad0e796314d6 (check 1.08s) 20200907 17:50:18 asr2/5700xt {"status":"C", "exponent":"99356317", "worktype":"PRP3", "res64":"af767eb4030a____", "residuetype":"1", "errors":{"gerbicz":"0"}, "fftlength":"5767168", "program":{"name":"gpuowl", "version":"v6.11364g36f4e2a"}, "user":"kriesel", "computer":"asr2/5700xt", "aid":"(redacted)", "timestamp":"20200907 22:50:18 UTC"} 2) There is a 1552444 iteration residue file, while in the restart it's looking for 1552443 at power 6. It seems there was a slight difference in computing how many iterations between the initial run and the restart or the original power and the fallback power. 3) It had already computed to 100% in the first run. And it recomputes from an indicated 99.84% to 100% in the restart. This is a minor production loss at 5 minutes 44 seconds. 4) The offby1, 1552444 vs. 1552443 prevents a power 6 proof from being generated in the restart. 5) Power 5 which would still save ~96% of a PRP DC is not attempted in the restart, or supported. (It might have the off by one, or more, issue too.) Admittedly this should be a rare case. Even power 4 would represent an occasional substantial savings over a complete DC as result of error. 6) For power 8, topk would be the next multiple of 256 above p which is 99356416 for p~99356317. Topk/256 for power 8 would be 388111. Saved residues would be at iterations that are multiples of that. Four times 388111=1552444, the first saved for power 6. The initial run goes past 99356416 to 99356800, presumably because of block size 400. But the restart computes only to 99356400, one less block for some reason. 99356400/256 = 388110.9375. Four times that is 1552443.75 which apparently got truncated to 1552443 for the power 6 restart. Or the restart proof attempts compute iteration count independently for each power ignoring the history of the exponent's run, or any need to ensure powers of 2 between iterations for different power proofs. If the restart omits the ceiling function, 99356317/256=388110.61328125; 4 times that is 1552442.453125, unlikely to produce 1552443 for power 6. So I suspect there's no way currently to save the proof. I still have all the files generated, and have not yet reported the PRP result. If in a future version, gpuowl computed topk for its maximum supported power (currently 9), then derived the specified power's iteration count for residues saved from multiples of that, some iteration multiples would be more reliably interchangeable among powers, improving fallback to lower powers upon an error. As is, topk/2^power for p=99356317 = power, first residue save, proposed, nearest multiple from current power8 default; 9 194056 194056 na 8 388111 388112 388111 7 776222 776224 776222 6 1552443 1552448 1552444 5 3104885 3104896 3104888 4 6209770 6209792 6209776 Last fiddled with by kriesel on 20200908 at 01:54 
20200908, 12:10  #28  
Random Account
Aug 2009
U.S.A.
7^{2}×37 Posts 
It seems I have ran into another oddity. gpuOwl is refusing to run PRPCF tests:
Quote:


20200908, 12:41  #29 
Einyen
Dec 2003
Denmark
7·431 Posts 
Gpuowl can only do PRP tests, not PRPCF test where 1 or more factors are known and testing the remaining cofactor.

20200908, 15:28  #30 
Random Account
Aug 2009
U.S.A.
7^{2}×37 Posts 
The assignment lines in worktodo begin with "PRP" only. I does not know the difference big or small. I have been running CF's, with known factor(s), since George began the certification process with Prime95 v30.x. The problem must be something else...

20200908, 17:00  #31 
"TF79LL86GIMPS96gpu17"
Mar 2017
US midwest
3^{2}·7^{2}·11 Posts 
Gpuowl not running PRPCF which it does not support at all, is not an oddity. Especially when the worktodo line says PRP. PRPCF is not an implemented work type in gpuowl. It's likely that giving it known factors in the worktodo line is confusing the input parser that was not written to handle such data. Other types of input error will also give the error message reported or similar, such as omitting AID or a placeholder 0 instead of AID; it shifts k,b,n,c, etc. into unintended nonmatching variables. Worktodo entry formats are described in https://www.mersenneforum.org/showpo...8&postcount=22
There is no utility to running a PRP test in gpuowl for something with a known factor. Nor in attempting to run a computation type in gpuowl that gpuowl does not implement, such as PRPCF. Last fiddled with by kriesel on 20200908 at 17:04 
20200908, 17:49  #32  
Random Account
Aug 2009
U.S.A.
1813_{10} Posts 
Quote:
Quote:
In Prime95, I have my work type set to "First time PRP on Mersenne cofactors." If these are first time tests, then why do all the assignments I get have factors? Manual reservations are the same. 

20200908, 21:17  #33  
"TF79LL86GIMPS96gpu17"
Mar 2017
US midwest
3^{2}·7^{2}·11 Posts 
Quote:
A first time PRPCF test of Mwhatever/"previously known factors, newfactor" would tell whether the cofactor is still composite, or a prime. PRP of composite Mwhatever will return composite no matter how many factors are known or unknown. And a type 1 PRP test's res64 will match a type 5 PRPCF run if both are correct, independently of how many factors are input into the PRPCF run done by software that supports it, because that's a property of type 5 PRP residue tests. Last fiddled with by kriesel on 20200908 at 21:47 

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