I have 550 watts cooler master old supply or i have r9380 4gb gpu when am do normal task such as browsing downloading etc psu fan 120mm big fan spin normal still little loud but when am play games such as gta v get cry 4 etc psu fan begin spin so fast and loud is that a problem??any danger?or it's abnormal? +12v stays in 11.54 11.74 and 11.96 minimum 11.54
Its not a problem, first of all 11.54 is okay, playing these high end games that too on good GPU like yours does makes it draw more power. Now more power generates more heat in the PSU, As a result the fan automatically increases its RPM to dissipate that extra heat, so more more speed and more noisy. I will recommend u to give your PSU a little cleaning and remove as must dust as possible without opening it.
The amount of heat being dissipated by the PSU is proportional to the amount of power being delivered. Power consumption goes up when gaming, so power dissipated by the PSU goes up, it gets hotter, fans ramp up to compensate.
I don't think so, normally cooler master PSU are very well build, they do come with good quality components. A GPU like R9 380 can easily work on a genuine 550w PSU. Try cleaning the PSU first, if that does not help get your PSU checked by any certified hardware technician. But I think a proper cleaning should help in keeping the noise low.
Drawing 89 W at idle would be terrible, I very much doubt that's the case.
My best guesses:
1) HW monitor is simply inaccurate
2) HW monitor is reporting the power draw going through the mobo PCIe (although this should be 75 W max according to spec), but doesn't include power being delivered by additional 6/8 pin power connectors.