I have only used the device occasionally to check or adjust the air pressure on the car tyres. This is quite slow and the device makes a loud, unpleasant noise. I switched it on once today without connecting the hose to a tyre valve and noticed that the air flow is very weak. A lot of noise for little air! In my opinion, absolutely not suitable for blowing out a PC case.
It's a small handy device, a bit noisy but good. I think it will also work for PC cleaning but I have never tried it. I need it to blow out the irrigation system on the terrace before winter....