System Idle Power Consumption

TrueNAS General
1

Hi All,

Following on from this thread on the old forums…

I’m just wondering what everyone’s idle power consumption is, and what hardware you’re running?

My system (in my signature) sits around 120W at idle.

That seems somewhat high compare to others that I’ve read.
I’m trying to understand what could be causing this…

According to the spec sheet of my HDDs, they should account for about 42W (5.3W x 8). That leaves about 78W unaccounted for. My CPU (E3-1225V3) has a TDP of 84W, but it shouldn’t be drawing that continuously, as 90% of the time it’s just idling.

Any ideas or comments?

2

for me: 38~40w, with the system in signature and 4 fan.
120w are really a bit high IMHO… how do you check that?

3

I have the power cord of my server plugged into an external power meter (Kill-A-Watt) style.

4

Are you sure it’s 5.3W? It very much depends on the type of ST6000… per the Seagate datasheet, the average power / idle power consumption of recent versions of that drive is between 8.1 and 7.3W each. Given how chatty TrueNAS is with its drives, I imagine the higher end is more likely than the lower end.

FWIW, my NAS is running around 110W with 8 HDD (Helium filled) and another 4 SSDs plus assorted fans, SLOG NVME, SATADOMs, etc.

5

I just double checked the model number (ST6000VN0033) and cross-referenced it with the data sheet.

Average Operating Power = 8.1 W
Idle Power = 7.2 W
Standby/Sleep = 0.6W

That would give me somewhere in the range of 58 - 65W. So a bit higher than 42W. The remaining 60W would be divided between the CPU, Motherboard, two SSDs, and a handful of case fans.

Does that sound accurate? Seems to match up a little closer to your system.

I found this write up about configuring CPU power modes in TrueNAS Core. I set the appropriate options in Tunables and rebooted the system.

Additional, I have also set all of the drives to use Advanced Power Management - Level 128 (minimum power usage without standby).

My power draw is around the 105 - 110W mark.

6

The PSU has a large impact on this as well. Your drives may draw 8W @ 12VDC ea but depending on the PSU power conversion efficiency at 100W, you may have to add an additional 20% on top of that. Only titanium grade PSUs have decent power conversion at the low end of their capacity range. Most PSUs only get efficient at 25% or more of their max capacity power draw.

I saw that here first hand when I compared the plug load of my NAS on a Corsair 500w platinum vs. a 650w Seasonic titanium. The latter resulted in a lower power draw, all other things being equal even though the higher total capacity of the Seasonic put it at a disadvantage.

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