[yablak]

... and 1-2% improvement in performance via the register allocator.

[changoplatanero]

If google has 10 million servers then a 2% improvement would be like freeing up 200,000 servers. That's a significant amount of value added!

[DannyBee]

It usually makes more sense to think in terms of cores rather than servers, because server density has always been increasing :)

[kevincox]

If Google has 100 data centers they can sell 2 of them.

[vardump]

In this day and age, that's a pretty large compiled code performance improvement from just one feature.

[JonChesterfield]

Across the board improvements from changing register allocators is surprisingly difficult to get. Couple of percent sounds great.

It's usually done heuristically in a fashion that scales badly with how many instructions you're considering at a time so it's really easy to overfit to today's benchmark.