The Performance Impact Of Spectre Mitigation On POWER9
Written by Michael Larabel in Software on 11 November 2018 at 04:30 PM EST. Page 3 of 4. 16 Comments.
The Cython performance was very noticeably impacted by the kernel+user protection.
While in the simple C-written AOBench renderer, having full protection only slowed down that benchmark by a few seconds.
The ray-tracing performance also slowed down by a few seconds with the full protection.
The full protection impacted the LLVM build times by a very small amount.
In the Stockfish chess benchmark having full Spectre protection slowed down its performance by about 5%. Though in these tests that are simply CPU heavy, on the x86_64 side we haven't seen much deviation in those numbers from Spectre mitigations.