[adaptives]

Using the pieces you built as you move along is a great idea, and an opportunity to understand the optimizations required to make them performant.

I think one reason, why they may insist is because, the basic pieces you built will be in HDL, while if you use the ones provided by the software, they will be in the form of compiled Java code. Perhaps that is one of the reasons why the books pieces will be faster/

[scorpioxy]

I finished the book a few months ago, and yes that is the main reason.

I wanted to test the whole finished stack using only my components so I did run it using only what I built. It ran but was around 10x slower, mainly the graphics tests. I did optimise the performance of the basic drawing algorithms using faster ones but, naturally, it was still much slower than the java implementation.

Another advantage of using your built components is that it helped me uncover some bugs which I only noticed when you ran something as complex as the pong example.