Smart Sim

"Smart Sim" is the default mode that Raidbots uses for larger simulations. It was inspired by AutoSimc and uses a multi-stage approach using increasing precision to run sims faster.

For massive sims the basic idea is to run a series of sims — initially you run very fast but low precision sims, then you choose the winners from that round, increase the precision, and run another round. Eventually you can determine the winner(s) at a high precision without wasting valuable CPU time on bad combinations.

Low precision sims can be run stupidly fast. Instead of requiring 10,000 or more iterations, often only 100–200 iterations are needed to be able to quickly filter out low performing gear sets. The better candidates then get run at a higher precision using more iterations to figure out the next set of winners, and so on.

Raidbots is using 3 stages at 1%, 0.2%, and 0.05% error margins.

A Note About Gem/Enchant Sims

One thing to note — sims where you choose multiple gems or enchants to test may take significantly longer to run than ones with just gear/talents.

Gems and enchants tend to provide a much smaller change in your overall DPS which means that more combinations will be at higher precision. Depending on how many sockets you have or how many gems/enchants you choose, Top Gear can take 10x longer (or more) to finish.

In general, I recommend running gem/enchant optimization sims separately from gear/talent runs — you’ll get the results you’re looking for more quickly.

Smart Sim + Everything Else

For non-massive sims (Stat Weights, Gear Compare, basically everything else aside from Top Gear and some large Advanced sims), Smart Sim helps ensure that you’re getting precise results. Instead of using a static iteration amount, it will run using 0.05% margin of error.

This means that if you sim multiple classes and you like to have the same precision on all of your sims, you won’t have to manually fiddle with the Iterations option and/or “waste” iterations in Top Gear by using a higher value than you need (Top Gear and Advanced treat all gear sets as 5k iterations for determining iteration limits).

0.05% target error may be significantly more precise than what the defaults previously provided and so smaller sims may end up taking more time than before. I’ll be listening to feedback very carefully to see if there are strong feelings about speed vs precision from you all.