[trhway]

the opposition usually sounds like this - "Microbenchmarks lie". On one of the past projects, the leading engineers and architects just loved that phrase and voiced it like a deep profound truth understanding of which was a hallmark of belonging to their circle of chosen. Any specific measurements showing issues with the supposedly brilliant architecture and implementation choices of that project (with many of these choices following the latest "best practices" fads published by some venerable technologists) were dismissed by that phrase just like by magic. Naturally that was one of the slowest, not to mention buggy, projects in my experience, and working in the enterprise space i've seen my share of slow and buggy.

[a1369209993]

Except that's not opposition? Microbenchmarks do, always, lie; you need to measure the performance of your actual, real code that you're actually caring about the speed of.

[stephc_int13]

Microbenchmarks are not lying, but they can be misleading...

The most frequent problem is selecting the fastest solution with a microbenchmark and creating a lot of unnecessary cache eviction/pollution, sometimes on the code cache, sometimes on L1/L2 or both...

Microbenchmarks are good to explore the optimization space, but the final decision should be made with the full execution context in mind.