Jump to content
Search In
  • More options...
Find results that contain...
Find results in...

[Guide] Is a Certified PSU worth it?

First of all, this guide will be covering only the aspect of efficiency and power requirements.  If you are looking for a guide on quality, please look elsewhere.

 

This guide aims to answer "should I upgrade my PSU to a more efficient 80+ gold (or platinum, etc.) model, and if so, which one?"

If you would like to know more about this standard and what each one means for the rated efficiency, see this post here.

 

The Calculations

The cost each year of operating the computer will be given by the following equation in every situation:

 

Untitled.png

Untitled2.png

 

So together we have

 

Untitled3.png

 

Generally speaking, if the yearly cost of operating the power supply is greater than the cost of a more efficient power supply over the number of years you expect to use it for, you should get a better one.  But how can we know if it is actually cheaper?  Time for some examples!

 

Consider a light user

  • System components draw of 150 W
  • Time spent on PC: 4 hours per day, 5 days a week, 52 weeks per year = 4 * 5 * 52 = 1040 hours per year
  • Lets assume power costs $0.12 per kWh, and that this user is comparing an 80% efficient PSU with a 90% efficient PSU.

Yearly cost of running 80% efficient PSU: (150 W / 0.80) x (1040 h) x (0.12 $/kWh) x (0.001 kWh/Wh) = $23.40

(That last part is added as a conversion from kWh to Wh)

 

Yearly cost of running 90% efficient PSU: (150 W / 0.90) x (1040 h) x (0.12 $/kWh) x (0.001 kWh/Wh) = $20.80

 

That's a yearly savings of $2.60 ($23.40 - $20.80) which is hardly anything at all!  This shows that if you are a very light user, it's not likely worth upgrading your PSU, since the cost of a new one could be well over $100, and you'd have to use the computer for decades to make that back!

 

Consider a heavy user

  • System components draw of 450 W
  • Time spent on PC: 24 hours per day, 7 days a week, 52 weeks per year = 24 * 7 * 52 = 8736 hours per year
  • Lets assume again that power costs $0.12 per kWh, and that this user is comparing an 80% efficient PSU with a 90% efficient PSU.

Yearly cost of running 80% efficient PSU: (450 W / 0.80) x (8736 h) x (0.12 $/kWh) x (0.001 kWh/Wh) = $589.68

 

Yearly cost of running 90% efficient PSU: (450 W / 0.90) x (8736 h) x (0.12 $/kWh) x (0.001 kWh/Wh) = $524.16

 

That's a yearly savings of $65.52 which is considerably more significant!  This shows that if you are a heavy user, it could be worth upgrading your PSU, especially if your system draws even more power than this, and/or your current PSU is even less efficient, and/or power is even more expensive where you live.

 

If math is not your strong suit, you can use the spreadsheet I've attached below.  It comes pre-filled with the numbers for the light user example, and you can adjust them to match your situation.

 

Book1.xlsx

 

I hope this was helpful!

Solve your own audio issues  |  First Steps with RPi 3  |  Humidity & Condensation  |  Sleep & Hibernation  |  Overclocking RAM  |  Making Backups  |  Displays  |  4K / 8K / 16K / etc.  |  Do I need 80+ Platinum?

If you can read this you're using the wrong theme.  You can change it at the bottom.

Link to post
Share on other sites
  • 5 months later...
On 6/1/2016 at 6:05 PM, Ryan_Vickers said:

That's a yearly savings of $65.52 which is considerably more significant

which is probably the money you'd spend on getting a more efficient PSU anyways (bit of an exaggeration but still)

PSU Tier List LTT Gender Survey

LTT's self-appointed memelord

Always up for a game of chess

See @STRMfrmXMN @Energycore or @Starelementpoke for PSU needs

See @deXxterlab97 for blue fetishes (if that's your thing)

See @ShadowTechXTS for cats

@Implosivetech's got you covered for all your graphic design needs

And lastly, never put a CX green series PSU in a high end build https://youtu.be/Oybz5Q-If9M?t=7

 

Link to post
Share on other sites
1 hour ago, wrathoftheturkey said:

which is probably the money you'd spend on getting a more efficient PSU anyways (bit of an exaggeration but still)

Exactly my point ;)

If more efficiency would save you that much, better to just buy a better one since it will pay for itself in a year and save you money after that.

Solve your own audio issues  |  First Steps with RPi 3  |  Humidity & Condensation  |  Sleep & Hibernation  |  Overclocking RAM  |  Making Backups  |  Displays  |  4K / 8K / 16K / etc.  |  Do I need 80+ Platinum?

If you can read this you're using the wrong theme.  You can change it at the bottom.

Link to post
Share on other sites

I want to add a few things before a smarmy person does it. (does that make me smarmy as well? :3 )

 

PSU efficiency ratings start at 20% load. So anything below that is not guaranteed to be at least the rating on the sticker. Except for 80 PLUS Titanium which is guaranteed to be 90% at 10% load. As an aside, desktop PSUs are typically most efficient at 50% load: https://en.wikipedia.org/wiki/80_Plus#Efficiency_level_certifications

Link to post
Share on other sites
38 minutes ago, M.Yurizaki said:

I want to add a few things before a smarmy person does it. (does that make me smarmy as well? :3 )

 

PSU efficiency ratings start at 20% load. So anything below that is not guaranteed to be at least the rating on the sticker. Except for 80 PLUS Titanium which is guaranteed to be 90% at 10% load. As an aside, desktop PSUs are typically most efficient at 50% load: https://en.wikipedia.org/wiki/80_Plus#Efficiency_level_certifications

Yes, good thing to keep in mind.  For the very light user who's system might never draw more than 200W, a 1500 W PSU could actually be less efficient than a smaller one, even if the smaller one isn't rated as well.

Solve your own audio issues  |  First Steps with RPi 3  |  Humidity & Condensation  |  Sleep & Hibernation  |  Overclocking RAM  |  Making Backups  |  Displays  |  4K / 8K / 16K / etc.  |  Do I need 80+ Platinum?

If you can read this you're using the wrong theme.  You can change it at the bottom.

Link to post
Share on other sites
  • 8 months later...

You should pin your own post.

Helpful Links: PSU Tier List | Why not group reg? | Avoid the EVGA G3 | EVGA BR/BT? no. noooo. | How much power do I need?

Helios EVO (Main Desktop) | Delta (Laptop) | Galaxy S21 Ultra | Pacific Spirit XT (Server)

 

Specs
Spoiler

 

Helios EVO (Main):

AMD Ryzen™ 7 3800X | 32GB G.Skill Ripjaws V / Team T-Force DDR4-3000 | ASUS STRIX B550-A GAMING | ASUS Dual Radeon RX 6700 XT 12GB GPU | NZXT H510 | EVGA G5 650W | MasterLiquid ML240L | 2x 2TB HDD | 256GB SX6000 Pro SSD | 3x Corsair SP120 RGB

 

Pacific Spirit XT - Server

Intel Core™ i7-8700K (Won at LTX, signed by Dennis) | GIGABYTE Z370 AORUS GAMING 5 | 16GB Team Vulcan DDR4-3000 | Intel UrfpsgonHD 630 | Define C TG | Corsair CX450M

 

Delta - Laptop

ASUS TUF Dash F15 - Intel Core™ i7-11370H | 16GB DDR4 | RTX 3060 | 500GB NVMe SSD | 200W Brick | 65W USB-PD Charger

 


 

Intel is bringing DDR4 to the mainstream with the Intel® Core™ i5 6600K and i7 6700K processors. Learn more by clicking the link in the description below.

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×