biggest problem with roping is when bot does a trade, and spawns another minion (in case of deathrattle, or something else) it will try to recalculate the board for remaining moves.
You can get around it by disabling syncboard in config file, the bot will never recalculate the board after change state. But it could create misplays (or less optimal plays)
Im running 3570k @ 4.2Ghz ,16gb ram, My config file only change allow for 4GB ram to be consumed (but it never does)
The bot doesnt rope too often in my opinion unless it recalculates board at least once. Even when it ropes, i would say 95% of the time, it will finish it's moves before time is up.