The default for cgminer is 120sec.
And I have no god damn clue what scan-time is

cgminer --help
Yeah, I read directly from the readme file but still cant understand the meaning of :
Upper bound on time spent scanning current work, in seconds (default: -1) Scan current work for what? Also, we use 1 not -1.
Couldn't help myself... now rejects are about 32% with the defaults after an hour.
Will trial:
"scan-time": "1",
"expiry": "1",
"queue": "5",
Hmm.. My WUs dropped after these settings. I ll try the low mem command.
I get over 90% WU. There doesn't seem to be any right answer for everyone, you just have to see what works for your system. Plus you have to run it for more than 20 minutes to get your real rates.
Yup, looks like it. Anyway, I ll leave it for the night with
"scan-time": "1",
"expiry": "120",
"queue": "0",
and see what happens in the morning