Arista PSU Fan Swap

Skud

Active Member
Jan 3, 2012
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Anyone had luck in swapping out the stock fans in the 500w model PSU? I picked up a 7050sx and have been trying to quiet it down.

With the fan override at 30% the switch itself is quite nice but the PSU fans are a good bit louder and to top it off it’s not a good loud. They’re whiny.
The stock fans are the typical FFB0412UHN Deltas (18k RPM). I typically like to replace fans with one or two models down from stock. This usually results in good cooling and acceptable noise. I’ve tried SHNs, VHNs, and the Nidec equivalent of the VHN (~9k RPM max). All seem to run the same speed once the fans spin down.

The only conclusion I can make is that the PSU has a set RPM it looks for instead of just setting a PWM duty cycle. It will spin the fan to whatever cycle it wants to get the desired RPM.

Normally I really hate just throwing a Noctua in because I feel they compromise airflow too much and I want to keep a level of safety if I ever needed it. However, I feel that may be the only solution? The switch still runs cold with everything set to 30%. I don’t think I’ve ever seen the PSU temp over 35C.

Riley
 

Skud

Active Member
Jan 3, 2012
115
54
28
Well, seems to work fine. I replaced both PSU fans with Noctuas and they're not too bad. I'll have to keep a close eye on it. The switch doesn't seem to mind either..

Code:
localhost(config)#sho system environment all
System temperature status is: Ok
                                                                 Alert  Critical
                                               Temp    Setpoint  Limit     Limit
Sensor  Description                             (C)         (C)    (C)       (C)
------- ----------------------------------- ------- ----------- ------ ---------
1       Cpu temp sensor                        35.1   (60) 60.0     90        95
2       Cpu board temp sensor                  25.0   (55) 55.0     75        80
3       Back-panel temp sensor                 21.0   (50) 50.0     75        85
4       Board sensor                           36.0  (N/A) 35.8     55        70
5       Front-panel temp sensor                30.9  (N/A) 42.2     65        75
6       Trident Bottom Right Outer             43.3  (N/A) 65.0    100       110
7       Trident Bottom Left Outer              42.3  (N/A) 65.0    100       110
8       Trident Top Left Outer                 42.8  (N/A) 65.0    100       110
9       Trident Top Right Outer                44.4  (N/A) 65.0    100       110
10      Trident Bottom Right Inner             43.3  (N/A) 65.0    100       110
11      Trident Bottom Left Inner              42.3  (N/A) 65.0    100       110
12      Trident Top Left Inner                 42.3  (N/A) 65.0    100       110
13      Trident Top Right Inner                43.3  (N/A) 65.0    100       110

PowerSupply 1:
                                                                 Alert  Critical
                                               Temp    Setpoint  Limit     Limit
Sensor  Description                             (C)         (C)    (C)       (C)
------- ----------------------------------- ------- ----------- ------ ---------
1       Hotspot                                41.0   (80) 80.0     95       100
2       Inlet                                  21.0   (55) 55.0     70        75

PowerSupply 2:
                                                                 Alert  Critical
                                               Temp    Setpoint  Limit     Limit
Sensor  Description                             (C)         (C)    (C)       (C)
------- ----------------------------------- ------- ----------- ------ ---------
1       Hotspot                                42.0   (80) 80.0     95       100
2       Inlet                                  22.0   (55) 55.0     70        75

System cooling status is: Ok
Ambient temperature: 21C
Fan speed override mode enabled at 30%
Airflow: port-side exhaust
                      Config Actual         Speed      Stable
Fan            Status  Speed  Speed  Uptime Stability  Uptime
-------------- ------ ------ ------ ------- --------- -------
1/1            Ok        30%    29% 2:46:25 Stable    2:45:44
2/1            Ok        30%    30% 2:46:25 Stable    2:45:46
3/1            Ok        30%    29% 2:46:25 Stable    2:45:44
4/1            Ok        30%    30% 2:46:25 Stable    2:45:44
PowerSupply1/1 Ok        30%    23% 2:01:33 Stable    2:00:50
PowerSupply2/1 Ok        30%    24% 2:46:05 Stable    2:45:22

Power                        Input  Output  Output
Supply Model       Capacity Current Current  Power Status  Uptime
------ ----------- -------- ------- ------- ------ ------ -------
1      PWR-500AC-R     500W   0.35A   2.60A  31.2W Ok     2:01:33
2      PWR-500AC-R     500W   0.39A   3.05A  36.7W Ok     2:46:05
Total  --             1000W      --      --  67.9W --          --