Parallell processing does not use additional engines, it will only create multiple child processes within each engine thread.
To illustrate what @david_r said:
All done on a FME Clould 2017 Starter instance (2 engines)
Job 752 is without parallel processing, 753 and 754 are run simultaneously with Moderate parallel processing, 755 is run by itself, also with Moderate parallel processing.
The fact I was able to start 754 while 753 was already running indicates it (753) didn't grab that additional engine.
Parallell processing does not use additional engines, it will only create multiple child processes within each engine thread.
Thanks for the clarification @david_r
To illustrate what @david_r said:
All done on a FME Clould 2017 Starter instance (2 engines)
Job 752 is without parallel processing, 753 and 754 are run simultaneously with Moderate parallel processing, 755 is run by itself, also with Moderate parallel processing.
The fact I was able to start 754 while 753 was already running indicates it (753) didn't grab that additional engine.
Thanks for the confirmation Hans @redgeographics
p.s., cool, we can now accept multiple answers !