PSU for DIY NAS

[GrayTech]

Yesterday I moved my NAS from a Dell Prebuild to a custom PC. I kept my Pentium G3240, 2x2GB RAM (which is totally enough for what I'm doing) and my drives, basically the only things that changed were the Case, motherboard and PSU. The Dell Motherboard and PSU both use proprietary connectors. I used an beQuiet! 580W PSU since I had one lying around but it is totally overkill for my 30-40W NAS. Therefore I want to get a new reliable PSU which is more suitable for the system.

Efficiency is really important since electricity is expensive where I live.

[artuc]

16 hours ago, GrayTech said:

Efficiency is really important since electricity is expensive where I live.

If you look at a lot of PSUs and then check their efficiency curves there is often not a lot in it. Once you get to gold, platinum and titanium it is typically only a few % in it. They're squeezing out all they can at this point.

 

Some power supplies may reach higher efficiency but not be certified for it or are just under at certain loads, which reviews will mention.

 

Also with light loads like your say 50W that efficiency difference is trivial to your power bill. No point chasing a few % efficiency for twice the price. 

 

Depending on the age of the PSU, if you have other systems for it to go to etc. If it would just be lying around, given cheap and old components therefore low risk/consequence if it failed. I don't know that it would be worth replacing purely for efficiency reasons as the payback may never be there.

 

Ultimately crunch the numbers. Say at your hypothetical 50W, a very basic calculation if it's 55W vs 60W due to efficiency at my electricity prices at 24/7 runtime the difference is $12 a year, so given say $80 for a minimum quality of PSU (if not more expensive to exceed the efficiency of your current one), around 6.5 years to break even for a low end PSU.

 

Not worth it personally unless there is other factors.

[GrayTech]

10 hours ago, artuc said:

Not worth it personally unless there is other factors.

The other factor is that I want to use the 580W PSU for something else. 

 

I'm from Germany, according to the numbers I found on the internet, the average electricity (per kWh) cost is 0,338€ which is about 0,4$. I already tried some other PSUs which are rated for 350W or even lower and they added up to 10 Watts just because of their inefficiency. Not all of them were that bad, but non was acceptable. 10W for something that runs 24/7 add up to almost 30€/per year (at 0,338€/kWh). But keep in mind that the NAS will run for multiple years. And since I want to use the 580W PSU for something else, I can justify buying a new PSU for the NAS. Plus I get the added benifit of having a new PSU.

 

In addition to that, the efficiency of a PSU is always a curve, not a straight line. And especially under 10% or sometimes up to 20% the efficiency is pretty poor.

 

After thinking about it, I wasn't that clear about what I meant when I said that:

On 7/21/2021 at 1:00 PM, GrayTech said:

Efficiency is really important since electricity is expensive where I live.

I'm not looking for something crazy like 80+ Platinum. The only alternatives to the 580W 80+ silver PSU that I have at home are OEM PSUs from reputable business systems but my tesing showed that they all add about 5-10W. And I really don't want to use them since they are old. I would like to find something like my 290W Dell OEM PSU from my original NAS build which is efficent and reliable even though it has no official rating whatsoever. Sadly it has proprietary connectors and a lound fan.

[akio123008]

1 hour ago, GrayTech said:

Not all of them were that bad, but non was acceptable. 10W for something that runs 24/7 add up to almost 30€/per year (at 0,338€/kWh).

Damn 30 euros a year. Big deal. That certainly justifies buying a 100 euro power supply (oh wait).

 

Here's another strategy; just don't leave it on 24/7. I have a NAS too and I only power it up when I need to access something on it. All the things I need often are on my computer, the NAS is for long term storage and I really don't need it running all the time. I have a remote button to power it up without crawling into my "server area".

 

Looking the specs of your NAS I can't imagine this thing is very critical and I suspect you could probably get away with not running it all the time.

[--SID--]

be quiet! Pure Power 11 400w and Bitfenix Formula Gold 450w are efficient at low loads. The Bitfenix is by far the better psu.

[GrayTech]

43 minutes ago, akio123008 said:

Damn 30 euros a year. Big deal. That certainly justifies buying a 100 euro power supply (oh wait).

I NEED the 580W PSU for something else. The alternative to "buying a new PSU" is "not having a PSU at all". Because I won't use those 10-15 year old OEM PSUs in the one server which stores ALL my data. (Of course I do make regular backups).

Basically I need a PSU anyways and I want something somewhat efficient. Is there anything wrong with it? I'm not buying a new PSU just for "saving a few euros or whatever each year". And since I don't need a high wattage unit, I don't have to spend 100€ to get a decent quality unit.

 

48 minutes ago, akio123008 said:

Looking the specs of your NAS I can't imagine this thing is very critical and I suspect you could probably get away with not running it all the time.

Don't judge this NAS by its specs. (BTW yesterday I upgraded it to an i5 4440 and 2x4GB RAM cause why not I had them lying around.) This NAS will carry all of my data, there will be non on of my other PCs so I have everything at one place.

 

You are absoultely right. This system will be powered down when I don't use it (e.g. at night).

[akio123008]

40 minutes ago, GrayTech said:

This NAS will carry all of my data, there will be non on of my other PCs so I have everything at one place.

I mean so is a lot of my stuff but I don't need to access most of it on a daily basis. 

 

40 minutes ago, GrayTech said:

I NEED the 580W PSU for something else. The alternative to "buying a new PSU" is "not having a PSU at all".

Yes but I thought:

3 hours ago, GrayTech said:

I already tried some other PSUs which are rated for 350W or even lower and they added up to 10 Watts just because of their inefficiency.

that you already had some other smaller power supply but didn't use it due to the low efficiency? Or did you borrow that one just for testing?