When you have everything in place, the unit immediately lights up and allows you to change the speed of the attached fans. If you don’t have a fan on a certain channel or if the fan isn’t turning/working then the unit will start beeping at you until you sort the problem out, or disable that channel by pressing ‘mode’ until the right channel is selected and pressing in the jog wheel.
Each fan has its RPM displayed on it telling you how fast it’s rotating. To change the speed at which its rotating you simply select the fan channel and then rotate the jog wheel clockwise or anti-clockwise until your preferred RPM between 60 and 5940 is shown. Then you click ‘mode’ again, its set and saved.
This is where the unit starts acting strangely. To change the fan speed, I found that 60RPM is minimum while 5940 RPM is full speed. If you have a 1200 RPM fan and set it to 1200 RPM on the unit, it’ll actually be rotating lower than that (noticeable with LED fans). I found that the displayed RPM shouldn’t be trusted as every now and again it’ll drop to 0. Also, for a 1200 RPM, it’ll display that even if it’s barely rotating. The limiting the speed works fine as long as you don’t take the RPM shown as gospel.
You can’t – say – set a 1200 RPM fan to rotate at 1000 RPM and trust what the unit tells you it’s rotating at as it’s simply wrong. Fine tuning a fan to the correct speed isn’t really possible, and it would make more sense for Zalman to instead of having RPM, to have percent. Then you could have an accurate idea of what the fan is doing. That’s essentially what is being used currently, as 5940 RPM appears to mean 100% (12v) while 60 RPM is 0% (4v). Then, when you return to just viewing what the fan is rotating at, the current RPM could be shown.
I found that changing the fan speed actually became a chore, as I would have to check inside my case to make sure that the fan was really doing what I had told it to. Soon I came to learn that 60 RPM and 5940 RPM are really the only two options to pick, rather than trying to get a certain RPM.
Another major issue with the unit is the viewing angle. Both vertical and horizontal viewing angles are appalling, and if you aren’t directly in front of the unit then reading what it says is difficult. Considering this is what the fan controller relies on, it’s not a great idea to have a bad screen.
The power bar which displays how much power your PSU is sucking from the mains is quite cool, although ultimately useless. It’s nice to see how much your PC is pulling, but I wouldn’t trust its accuracy and the novelty wears off pretty rapidly. Unless you need to test the amount of power something is using regularly, this feature will be forgotten about after a few days.