[uo_throwaway]

I'll get those patches out soon. Outlands generally is running much more complex AI with much faster response targets, so in conjunction with the far more detailed map it is stressing RunUO much harder than previous shards. But as noted the primary CPU consumer is definitely the map searching. My changes don't entirely change the algorithm (I've adjusted the sector size), but rather take advantage of more recent C# features that are much friendlier to the JIT and shift several allocations to the stack.

I'd also like to move away from timers for mobiles and simply call a function on a subset of them (sector by sector) each tick. This is advantageous because it groups all of the processing for a set of nearby mobiles in game space together in time, so it should greatly improve the CPU cache hit rate during the map searches. That would also require moving RunUO to a constant tick rate, which I also have patches for.

If anything, my changes have made RunUO more single threaded (and eliminated some locks in doing so). This has proven to be faster than some of the previously highly parallel code because the contention was so bad. That's not to say that it couldn't be done in a way that did scale well, but I agree with you that it would put the code out of reach of hobbyists entirely. I think the code today strikes the right balance of approachability and performance. Thanks for all of your effort on this project!