If your request are huge. For example, imagine you need to read many huge files into memory. Whether you read one file after the other sequentially, or try to

If your request are huge. For example, imagine you need to read many huge files into memory. Whether you read one file after the other sequentially, or try to read all of them concurrently, won't make a difference, because your Disk/RAM bandwidth is going to be bottlenecked anyways. Trying to do this concurrently requires more work that won't pay off, so it might actually be slower.