Tuning ASP.NET

Here are a range of articles for tuning and ASP.NET server:

Performing an await on an async operation does not use a new thread (unless the implementation explicitly starts one). It is possible to write an write to disk asynchronously without using a new worker thread. This article explains why in detail.

Task.Run, TaskFactory.StartNew and ThreadPool.QueueUserWorkItem will use a worker thread.

Contention, poor performance on ASP.NET
ASP.NET Core best practices
Tuning ASP.NET Core and avoiding large memory allocations
ASP.NET Thread usage
Tuning IIS 10
How the garbage collector causes random slowness

IO

IO Completion Threads in more detail
IO Completion ports
Programming IOCP
IOCP and ASP.NET

Memory Management

Pooling memory buffers to avoid keep allocating memory on every request
Memory management and garbage collection
Using ArrayPool