This is probably old news, but the latest version of cgminer that I checked out from https://github.com/vthoang/cgminer.git is a lot newer than what I checked out just a few months ago.  In particular, cgminer always starts at 100mhz then incrementally increases the clockrate to what was set on the command line, so we can figure out the max clockrate more easily.  Pretty cool!  Happy 4-20!

[2018-04-20 01:42:13.988] GSD 3: start work @ 100.00MHz
 [2018-04-20 01:42:28.416] GSD 0: setting frequency to 125.00MHz
 [2018-04-20 01:42:28.619] GSD 1: setting frequency to 125.00MHz
 [2018-04-20 01:42:28.827] GSD 2: setting frequency to 125.00MHz
 [2018-04-20 01:42:29.033] GSD 3: setting frequency to 125.00MHz
 [2018-04-20 01:42:43.616] GSD 0: setting frequency to 150.00MHz
 [2018-04-20 01:42:43.802] GSD 1: setting frequency to 150.00MHz
 [2018-04-20 01:42:44.014] GSD 2: setting frequency to 150.00MHz
 [2018-04-20 01:42:44.203] GSD 3: setting frequency to 150.00MHz
 [2018-04-20 01:42:58.638] GSD 0: setting frequency to 175.00MHz
 [2018-04-20 01:42:58.829] GSD 1: setting frequency to 175.00MHz
 [2018-04-20 01:42:59.038] GSD 2: setting frequency to 175.00MHz
 [2018-04-20 01:42:59.225] GSD 3: setting frequency to 175.00MHz
 [2018-04-20 01:43:04.273] Pool 0 difficulty changed to 1638
 [2018-04-20 01:43:04.274] Stratum from pool 0 requested work restart
 [2018-04-20 01:43:13.659] GSD 0: setting frequency to 200.00MHz
 [2018-04-20 01:43:13.945] GSD 1: setting frequency to 200.00MHz
 [2018-04-20 01:43:14.092] GSD 2: setting frequency to 200.00MHz
 [2018-04-20 01:43:14.235] GSD 3: setting frequency to 200.00MHz
 [2018-04-20 01:43:28.725] GSD 0: setting frequency to 225.00MHz
 [2018-04-20 01:43:28.974] GSD 1: setting frequency to 225.00MHz
 [2018-04-20 01:43:29.121] GSD 2: setting frequency to 225.00MHz
 [2018-04-20 01:43:29.294] GSD 3: setting frequency to 225.00MHz