[cthalupa]

>Are there build optimizations for E3/V5 vs E5/V2 that could make such a difference?

Potentially, yes.

Either way you're not comparing apples to apples using packages from a 3rd party repo built for a different system.

Newer processors have different instruction sets (AVX is a big one). You'd want to make sure you're not only compiling it on each different platform, but also using a new enough compiler to support the instruction sets.

[erichileman]

Correct. We are going to build using the correct -march flags: https://gcc.gnu.org/onlinedocs/gcc/x86-Options.html

[erichileman]

>>gcc -march=native -Q --help=target

>>march=silvermont

gcc native thinks this e3 is silvermont, a low power SoC.

[erichileman]

We built 5.6 with -O2 -march=broadwell -mno=avx (had to remove, probably pecl ext issue).

There was about a 15% performance gain. Nothing that would explain the large difference between E3 and E5.