- May 29, 2011
Startup current of the drives 1,8 A (1,8 * 12 is 21,6 per driver)
Ah, there's a mistake. Startup current is additional power pulled on the 12V rail for spinup. Your drives also take power for normal operations, on the 5V rail, sometimes on the 12V rail too. Some drive manufacturers do actually report peak startup current on the 12V rail as the "startup current", while others expect you to add together the nominal and startup amps. These days, it's hard to find detailed information. Consider a typical hard drive to eat, oh, I dunno, maybe 4-6 watts for idle operation. The problem is that when you multiply that by your ten drives, you could be missing 40-60 watts in your calculation.
processor AMD EPYC 3301 TDP - 35 watt
And there's another, that's a 65 watt TDP part. That doesn't mean it'll actually USE 65 watts, but it's a ballpark approximation.
Anyways, one of the big reasons not to try to "right-size" your PSU to the exact number of watts you think you need is that it adds risk, but oversizing it somewhat is quite forgiving and offers some room for error.