Disclaimer - update to yacminer 3.5.0 is required to follow this advice...
You need to allocate more memory. 760 MB is not enough - Double it and go higher if you can. Use "--buffer-size 1664" instead of your thread concurrency setting. That will let you use more shaders without running out of memory. If you do that, you can push -R to ~3300 without any other changes to your config
tried compiling it now:
yacminer.c: In function ‘GetNfactor’:
yacminer.c:1090:11: error: ‘opt_n_scrypt’ undeclared (first use in this function)
else if (opt_n_scrypt)
^
yacminer.c:1090:11: note: each undeclared identifier is reported only once for each function it appears in
yacminer.c: In function ‘curses_print_status’:
yacminer.c:2297:27: error: ‘opt_n_scrypt’ undeclared (first use in this function)
if (opt_scrypt_chacha || opt_n_scrypt)
^
yacminer.c: In function ‘main’:
yacminer.c:7807:16: error: lvalue required as unary ‘&’ operand
opt_set_bool(&opt_scrypt);
^
yacminer.c:7808:20: error: ‘opt_n_scrypt’ undeclared (first use in this function)
opt_set_invbool(&opt_n_scrypt);
^
yacminer.c:7813:16: error: lvalue required as unary ‘&’ operand
opt_set_bool(&opt_scrypt);
^
yacminer.c:7814:19: error: lvalue required as unary ‘&’ operand
opt_set_invbool(&opt_scrypt_chacha);
^