I am still running NVIDIA GTX 775M, but if I do purcahse a new iMac, just hoping that there might be someone else who has gone down the path of compiling mfakto

Reference info
 

There are separate threads with reference info for mfaktc and for mfakto, at [url]https://www.mersenneforum.org/forumdisplay.php?f=154[/url]. The Concepts in GIMPS Trial Factoring post [url]https://www.mersenneforum.org/showpost.php?p=508523&postcount=6[/url] may be of particular interest.