d:\Backup\Temp1>mfaktc-win-64.exe --perftest mfaktc v0.21 (64bit built) Compiletime options THREADS_PER_BLOCK 256 SIEVE_SIZE_LIMIT 32kiB SIEVE_SIZE 193154bits SIEVE_SPLIT 250 MORE_CLASSES enabled Runtime options SievePrimes 25000 SievePrimesAdjust 1 SievePrimesMin 5000 SievePrimesMax 100000 NumStreams 3 CPUStreams 3 GridSize 3 GPU Sieving enabled GPUSievePrimes 82486 GPUSieveSize 64Mi bits GPUSieveProcessSize 16Ki bits Checkpoints enabled CheckpointDelay 300s WorkFileAddDelay disabled Stages enabled StopAfterFactor class PrintMode full V5UserID (none) ComputerID (none) AllowSleep no TimeStampInResults no CUDA version info binary compiled for CUDA 10.0 CUDA runtime version 10.0 CUDA driver version 11.10 CUDA device info name GeForce GTX 1060 3GB compute capability 6.1 max threads per block 1024 max shared memory per MP 98304 byte number of multiprocessors 9 clock rate (CUDA cores) 1784MHz memory clock rate: 4004MHz memory bus width: 192 bit Automatic parameters threads per grid 589824 GPUSievePrimes (adjusted) 82486 GPUsieve minimum exponent 1055144 running a simple selftest... Selftest statistics number of tests 107 successfull tests 107 selftest PASSED! Can't open workfile worktodo.txt ERROR: get_next_assignment(): can't open "worktodo.txt" d:\Backup\Temp1>