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Proper Power Supply Sizing Guidance

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Thanks for the guidelines. I'm attempting to apply them as I spec my first FreeNAS build.

Motherboard (SuperMicro MBD-A1SRi-2758F-O) = 25W
CPU (Intel Atom 2758) - 20W x 1.25 = 25W
RAM (2 x 8GB DDR3 204-pin) = 12W
SSD (Samsung 500GB) = ??
Fans (2 x 80mm) = 40W
HBA = 10W

TOTAL = 112W (not including SSD)

I'm not clear on how to determine the idle wattage for this system. But even with the SSDs being a ?, a 300W PSU would be more than adequate?
 

Jailer

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Ok I got a question for you knowledgeable types. :D

My server is running a PC Power and Cooling Turbo Cool 510. The 510 watt rating is the 50c continuous power rating. This power supply also lists in it's specs that it's rated for 650 watts for a maximum of 10 seconds. The +12v rail is listed as 34a continuous 38a peak. Would you trust 6 WD 3TB greens and 6 WD 6TB reds with this or go bigger?
 

rogerh

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Thanks for the guidelines. I'm attempting to apply them as I spec my first FreeNAS build.

Motherboard (SuperMicro MBD-A1SRi-2758F-O) = 25W
CPU (Intel Atom 2758) - 20W x 1.25 = 25W
RAM (2 x 8GB DDR3 204-pin) = 12W
SSD (Samsung 500GB) = ??
Fans (2 x 80mm) = 40W
HBA = 10W

TOTAL = 112W (not including SSD)

I'm not clear on how to determine the idle wattage for this system. But even with the SSDs being a ?, a 300W PSU would be more than adequate?
No chance you would want to add any further storage to the system, HDD or SSD? Using the HBA sort of implies you might. The power the SSD uses will be in its specs, but they don't apparently have any extra starting current, just idle and max power.
 

Bidule0hm

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My server is running a PC Power and Cooling Turbo Cool 510. The 510 watt rating is the 50c continuous power rating. This power supply also lists in it's specs that it's rated for 650 watts for a maximum of 10 seconds. The +12v rail is listed as 34a continuous 38a peak. Would you trust 6 WD 3TB greens and 6 WD 6TB reds with this or go bigger?
If fact I'd not trust this brand, whatever the wattage is, unless I see good tests and reviews... :D

@W4LKR Yeah, you're fine with a 300 W PSU for this. But I must warn you about using non-ECC RAM, see the link in my signature if you want more details ;)
 

jgreco

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No chance you would want to add any further storage to the system, HDD or SSD? Using the HBA sort of implies you might. The power the SSD uses will be in its specs, but they don't apparently have any extra starting current, just idle and max power.
It's also worth noting that a reasonable guess is acceptable for the purposes of sizing things. I've provided guidance here that is largely educated guesses based on years of observation. The real thing we're shooting for in this thread is to stomp out the complete failure to allow for spinup current that seems so many new users forget to include.
 

Jailer

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If fact I'd not trust this brand, whatever the wattage is, unless I see good tests and reviews... :D
It's about 7 or 8 years old but it's a pre OCZ unit. I've never found anything but glowing reviews on it and at the time it was supposed to be one of the best ATX power supplies made.
 

rogerh

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It's about 7 or 8 years old but it's a pre OCZ unit. I've never found anything but glowing reviews on it and at the time it was supposed to be one of the best ATX power supplies made.
I imported one of theirs in 1996 or 7, as there didn't seem to be anything as quiet and good quality available in the UK. It lasted until the last of my 20 power pin motherboards went out of use about 2010, and never got hot or misbehaved. May not have much to do with their more recent production, but they were aiming for a good reliability reputation.
 

Bidule0hm

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7 or 8 years old with 24/7 usage?
 

Jailer

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7 or 8 years old with 24/7 usage?
No it sat for about the last 3 or 4 years until I put it into service for my FreeNAS build. Before that it was used in my desktop.
 

Bidule0hm

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Ok, should be good then ;)
 

INCSlayer

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jgreco

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Wait, I thought zfs scrubs things. Wouldn't that clean the power for us? What if I rename my pool to 'power' then scrub it?
Do you really want to risk that I might be unusually cranky this morning?

Next person to taunt me gets a new avatar. Maybe this one!



:p
 
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Hi,
I run the math for my new planned array...

1) Total potential watts: 975,8 -> ~1000W
2) Total potential 12V amps: 81,31A -> ~90A
3) Average idle watts: 563,2 W -> ~600W

planned hardware:

I think my estimations with 2x 700W PSU was quiet good. :)

Flatterlight
 
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If you have to choose between a PSU with 92% or 85% efficiency, choose the first one. It cost more, but the price between them (BEP), is earned back within a year. And the savings went from then on.

In my calculations where

power supply 450W
stated consumption: 200W
PSU 1 92% price € 76.00
PSU 2 85% price € 61.00
price kWh € 0.22

PSU 1 € 1.15 per day
PSU 2 € 1.24

B.E.P.: 159 days
this means: 5.2 months
 

jgreco

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Those numbers I used, are actual. Only number what can be debate, is the kWh price en stated consumption.
 
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