The discussion resulting from my question has been most interesting &amp; most helpful! I'm saving it for future reference. The protein I'm working on almost has a missing loop - that is, someone finally managed to get crystals in which the previously missing residues were resolved.&nbsp; But someday, that won't be the case.<br><br>I have a 2.33GHz linux box, and I started my 514-residue dimeric protein on Rosetta relax&nbsp; a short time after lunch on Friday. The job finished sometime Saturday night or the early hours of Sunday morning. The MolProbity score was 1.93. <br><br>Thanks so much!<br><br>Irene