The server side can "pre-roll" resources and clients make a roll when mining the resource. The winner is the one that is closest or matches the pre-rolled value on the server. In situations where there's no contention the user is default the closest to the pre-roll. In situations where there is contention and events happen close together the precise timing isn't required.
The server also doesn't need super precise time slices. Some of that can be hidden on the client with animations, cooldown timers, and other visual tricks. An MMO will have different timing expectations than say a twitch shooter.
The server also doesn't need super precise time slices. Some of that can be hidden on the client with animations, cooldown timers, and other visual tricks. An MMO will have different timing expectations than say a twitch shooter.