There are cash awards for discovering a new Mersenne prime! Joining GIMPS is usually as simple as downloading and running the program, answering a few questions, and the program does the rest. Improvements to the hyperthread core detection.Faster factoring code using FMA if available.The new code will now do multithreaded trial factoring.Changes to default CPU cores assigned to each worker to optimize total throughput per system.New benchmarking routines to determine the optimal FFT code.Faster step 1 GCD for ECM and P-1 factoring.For non-base-2 PRP tests, there is a new option to run each iteration twice and rollback if a mismatch occurs.Because PRP tests are highly reliable, we now offer the option to do PRP tests instead of Lucas-Lehmer primality tests.PRP tests now support a type of low overhead error checking that almost guarantees correct results even on flaky hardware.Like LL tests, PRP tests now support shift counts to aid in running double-checks.GIMPS has a new sub-project - finding (probable) prime Mersenne cofactors.This replaces LL testing as the default work type More robust implementation of Gerbicz error checking in PRP tests.Modified torture test dialog box with new options and better understanding of the L1/L2/元 cache hierarchy.