The fans worked on my server. They are of different brand than showed in the pictures and has slightly lower CFM. But they still worked out pretty well.
I'm very sure these do not run wide open when properly installed but testing on a 12v line (red and black) you will get the full speed. If running in a server rack, and most likely will be speeds may adjust to temps. Using for projects these are loud when wide open but a speed adjuster can be easily installed. Very cool.