It is NOT ok & it can damage/kill his mobo!
hello i have a 0.9A delta connected to the mobo and so far no problem. typical cpu fans are like 0.2-0.3 amps, chipset fan is about the same so as long as you are under 2.1 amps its fine. besides most fan (cpu/chipset) don't run at their full speed so its draw less amps than that so its ok.
0.52A x 12V = 6.24watts on a fan header to a total max of 2.1 amps on all headers is 25.2 watts total for all fan headers.