Difference between cl and g++ compilers?

#include <iostream>
#include <algorithm>
#include <vector>
#include <chrono>

template<class Resolution = std::chrono::milliseconds>
class ExecutionTimer {
public:
    using Clock = std::conditional_t<std::chrono::high_resolution_clock::is_steady,
        std::chrono::high_resolution_clock,
        std::chrono::steady_clock>;
    ExecutionTimer() = default;

    ~ExecutionTimer() {
        std::cout
            << "Elapsed: "
            << std::chrono::duration_cast<Resolution>(Clock::now() - mStart).count()
            << std::endl;
    }
private:
    Clock::time_point mStart = Clock::now();
};

int main() {
    ExecutionTimer<> timer;

    std::vector<int> v(50000000);
    std::sort(std::begin(v), std::end(v));
    return 0;
}

I tried to compile the above C++ code with 2 different compiler and observed the difference in the Running time of both .exe files as
CL -> cl /ehsc Benchmark.cpp
364 (ms)
g++ -> g++ -std=c++17 Benchmark.cpp -o bench17
16565 (ms)
Can Some 1 tell me why there a huge difference?