Which is the best cracking mode?

[Snoopy]

well this should not be really the problem, unless you are using a real old/low spec graphiccard or somthing like a laptop (thats why i asked for output of hashcat -I , but never the less you could try the following, use your CPU instead of GPU by adding the following options (as normally there is more RAM built in than graphics RAM)

-D1 -d1

regarding rules, these are applied directly on your graphicscard so this should also be no problem even when using more rules