Just tested servo build from scratch. Rustc 2017-10-13-alt (default for servo master at that time)
RUSTFLAGS='-C codegen-units=16 -Z thinlto' ./mach build --release
Finished release [optimized] target(s) in 448.72 secs
./mach build --release
Finished release [optimized] target(s) in 1082.6 secs
Don’t really know how to test the performance in deterministic way, but quick internal profiling showed no major difference for few sites I’ve checked. Great work!
The setup: Ryzen 7 1700 @ 3.5GHz + mid level SATA SSD.