Skip to main content

Fibonacci algorithm performance testing in .NET languages.

I was doing a little tidy up of the some of the books under my desk and I started to flick through Foundations of F# by Robert Pickering. It's a great book and I started to flick through it. I spotted the Fibonacci sequence and it got me thinking. How could I waste some of my afternoon?

I did the algorithm in F# and then begun to wonder if something in C# would be faster. That got me thinking about how to accurately measure performance. In the end I went down a bit of a rabbit hole but I found some interesting results.



 The results above correspond to the names of the tests below. It's very difficult to create a true scientific test on your own computer but the tests were run an i5 Sandy Bridge with 8gb of ram. No other programs except Visual Studio and Windows 7 were running. I ran the test 5 times, each time it ran the tests 100,000 times and then it grouped on the test name and took the average and saved it to sheet 2 above. I then used a pivot table and aggregated / averaged again.

I was surprised and pleased that the F# methods seemed to run the fastest. Even more surprising was that some of the VB entries were next.

I wasn't surprised that the shorthand VB method was slower; even though really it should be just as fast as the C# shorthand equivalent if ? :. Obviously they don't boil down to the same thing in IL (I might just check that next).

It's worth noting that many of the results are really close together. They are in the correct order but are rounded to 4 decimal places. I think in most situations that's accurate enough.

The original algorithm was the fastest but as they were all so close; it's worth considering other things such as the most expressive syntax. As it turns out, I think the original F# algorithm is actually expressed the nicest way to by a long way.

Comments

Popular posts from this blog

Creating star ratings in HTML and Javascript

I'd searched around a little for some shortcuts to help in doing this but I couldn't find anything satisfactory that included the ability to pull the rating off again for saving. I'd ended up coming up with this rather cheeky solution. Hopefully it helps you too! This is my first post in a while (I stopped blogging properly about 8 years ago!) It's strange coming back to it. Blogger feels very crusty and old by todays standards too.

Make your objects immutable by default

More about the Good Dojo In my post last week , I discussed creating objects that are instantiated safely. Please go back and read if you are interested. At the end of the post, I mentioned that I'd also written the class so it was immutable when instantiated. This is important!!! I feel like a broken record in repeating this but I am sure at the time of writing your code, you aren't modifying your object all over the place and so are safe in the belief that protecting against mutability is overkill. Please remember though, your code could be around for a hell of a long time. You aren't writing your code for now... you are writing for the next fool that comes along (including you) . Nothing is more upsetting that coming back to fix a bug on some wonderfully crafted code to say "Who has butchered my code?!", but often you were involved at the start of the process. You made the code easy to modify, allowing objects to be used / reused / modified without thi

An instantiated object should be "ok"

I've been QA'ing quite a bit of work recently and one common theme I've noticed across both Java and C# projects I have been looking at is that we occasionally open ourselves up unessacarily to Exceptions by the way objects are being created. My general rule of thumb (which I have seen mentioned in a Pluralsight video recently but also always re-iterate in various Robust Software talks I have done) is that you shouldn't be able to create an object and then call a method or access a property that then throws an exception. At worst, it should return null (I'm not going to moan about that now). I've created an example below. We have two Dojos, one is good and one is bad. The bad dojo looks very familiar though. It's a little class written in the style that seems often encouraged. In fact, many classes start life as something like this. Then as years go on, you and other colleagues add more features to the class and it's instantiation becomes a second