Why make_shared slower than sharet_ptr

In each article it is written that make_shared is more efficient, than shared_ptr(new T), because of one memory allocation not two. But i try this code:

#include <cstdio>
#include <ctime>

#include <memory>
#include <vector>

static const size_t N = 1L << 25;

int main(void) {

    clock_t start = clock();
        for ( size_t rcx = 0; rcx < N; rcx++ ) {
            auto tmp = std::shared_ptr<std::vector<size_t>>( new std::vector<size_t>( 1024 ) );
        }
    clock_t end = clock();
    printf("shared_ptr with new: %lf\n", ((double)end - start) / CLOCKS_PER_SEC);

    start = clock();
        for ( size_t rcx = 0; rcx < N; rcx++ ) {
            auto tmp = std::make_shared<std::vector<size_t>>( 1024 );
        }
    end = clock();
    printf("make_shared: %lf\n", ((double)end - start) / CLOCKS_PER_SEC);

    return 0;
}

compile with:

g++ --std=c++14 -O2 test.cpp -o test

and got this result:

shared_ptr with new: 10.502945

make_shared: 18.581738

Same for boost::shared_ptr:

shared_ptr with new: 10.778537

make_shared: 18.962444

This have answer about LLVM's libc++ is broken, but i use libstdc++ from GNU. So, why make_shared is slower?

P.S. With -O3 optimization got this result:

shared_ptr with new: 5.482464

make_shared: 4.249722

same for boost::shared_ptr.