This is quite cool, but I must note that the 5x reported in the headline is the _runtime_ of the load balancing algorithm itself, not the load factor or throughput of the system or what have you.
> On average, it takes about 540 ms to re-balance the experts and achieves a load balance factor of 0.66 (calculated as the ratio of average to maximum tokens generated per GPU).
> ...
> We also consider a non-public reference implementation from a frontier lab that we have access to. This implementation avoids explicit iteration and reduces the rebalancing algorithm runtime to 19.6 ms while achieving the same balance factor as the open-source algorithm.
> ...
> The resulting algorithm matches the load balance factor of the other baselines while reducing runtime to just 3.7 ms, yielding a 5.0x speedup over the internal reference implementation.