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U# vs C#

U# is noticeably slower than regular C#, to benchmark it I decided to execute two scripts in U# and C#, one calculates the n-th Fibonacci number, the second one generates a maze.

To make those tests a bit fairer, I disable the C# compiler optimization, since the U# compiler does not optimize your scripts during compilation.

Recursive functions

For this test I executed a script that calculates the n-th Fibonacci number, the Fibonacci method looks like thisĀ 

public int FibonacciRecursive(int n)
	if (n <= 1)
		return n;
		return FibonacciRecursive(n - 1) + FibonacciRecursive(n - 2);

Since FibonacciRecursive is a recursive function, the [RecursiveMethod] attribute need to be added.

This is really a horrible way to calculates the n-th Fibonacci number because certain method calls get called multiple times, and the number of method calls rise very quickly :

  • Fibonacci(1) calls the Fibonacci method 1 time
  • Fibonacci(2) calls the Fibonacci method 3 times
  • Fibonacci(10) calls the Fibonacci method 177 times
  • Fibonacci(22) calls the Fibonacci method 57313 time

So I felt like this test is a great way to determine how well U# performs this task, and I executed Fibonacci(22) in C# and U#

C# time : 0.189 ms
U# time : 684.577 ms
U# was 3629 times slower!

Maze generator

In my "Circuit Master" world, I wrote a custom maze generator algorithm, which I unfortunately cannot share because the algorithm is about 1600 lines long.

I decided to compare the execution time of that algorithm because that would be a more realistic test, it uses pretty much everything (Unity functions, custom list implementations, for-loops, bit manipulations etc.).

The algorithm does not call any recursive functions, but implements a custom stack made out of a ring buffer (ttps:// which is a very fast container to build and read a stack

C# time : 1.609 ms
U# time : 972.712 ms
U# was 604 times slower!

Based on the previous results, we can see that U# is much slower than regular C#, so keeping your code optimized is even more important in U#!