Question Can you tell me what is the difference between the PWS-920P-1R and PWS-920P-SQ power supplies; and how loud (Dba) of the 2 power supplies? Answer Both PWS-920P-1R and PWS-920P-SQ power supplies can be used with 846TQ-R900 while PWS-920P-SQ is more quiets. PWS-920P-SQ: 23dBa at input power: 300~ 400W and PWS-920P-1R about 45dB. Was this FAQ helpful? YES      NO Enter Comments Below: Note: Your comments/feedback should be limited to this FAQ only. For technical support, please send an email to support@supermicro.com.  Enter your email address below if you'd like technical support staff to reply:  Please type the Captcha (no space) K Q E V FAQ Stats FAQ ID Related Category / Keyword Date Posted Code 17114 Peripherals: - Power Supply 09/27/13 TH     Print Answer