Add further note on why we do not use relaxed atomics.

NOTES.md

@@ -4,6 +4,20 @@ A collection of stuff that we noticed during development.
 Useful later on two write a project report and to go back
 in time to find out why certain decisions where made.
 
+## 06.05.2019 - Relaxed Atomics
+
+At the end of the atomic talk it is mentioned how the relaxed
+atomics correspond to modern hardware, stating that starting with
+ARMv8 and x86 there is no real need for relaxed atomics,
+as the 'strict' ordering has no real performance impact.
+
+We will therefore ignore this for now (taking some potential
+performance hits on our banana pi m2 ARMv7 architecture),
+as it adds a lot of complexity and introduces many possibilities
+for subtle concurrency bugs.
+TODO: find some papers on the topic in case we want to mention
+it in our project report.
+
 ## 06.05.2019 - Atomics
 
 Atomics are a big part to get lock-free code running and are also