F5F Stay Refreshed Hardware Desktop Calculating the power loss of a '80 Plus' PSU in Watts

Calculating the power loss of a '80 Plus' PSU in Watts

Calculating the power loss of a '80 Plus' PSU in Watts

G
Geartator
Member
61
10-04-2016, 07:42 AM
#1
The definition explains how the 80 Plus certification evaluates PSU performance under various loads. It states specific efficiency targets at 20%, 50%, and 100% loads. Your scenario involves a 470 Watt 80 Plus Bronze unit delivering 235 W at full load, which implies an efficiency of about 85% at that level. The question asks whether this suggests roughly 15% energy loss, bringing the output nearer to 200 W. This aligns with understanding the certification thresholds and your goal of reducing power draw for better efficiency.
G
Geartator
10-04-2016, 07:42 AM #1

The definition explains how the 80 Plus certification evaluates PSU performance under various loads. It states specific efficiency targets at 20%, 50%, and 100% loads. Your scenario involves a 470 Watt 80 Plus Bronze unit delivering 235 W at full load, which implies an efficiency of about 85% at that level. The question asks whether this suggests roughly 15% energy loss, bringing the output nearer to 200 W. This aligns with understanding the certification thresholds and your goal of reducing power draw for better efficiency.

_
_Killexx_
Member
104
10-04-2016, 08:40 PM
#2
the psu would continue supplying 235w to the system while consuming 276w from the wall. the gap between 235 and 276 represents the energy lost due to inefficiency or heat.
_
_Killexx_
10-04-2016, 08:40 PM #2

the psu would continue supplying 235w to the system while consuming 276w from the wall. the gap between 235 and 276 represents the energy lost due to inefficiency or heat.

P
Ploy
Junior Member
12
10-04-2016, 08:46 PM
#3
Ah - I see the issue, haven't I?
In my case where the PSU is drawing 235W at the wall, that's not the actual load at the PSU output (like a 50% load), but rather closer to 200W (a drop from about 15% of 235W).
But the overall concept still makes sense, yes? An 85% efficiency means roughly a 15% loss?
P
Ploy
10-04-2016, 08:46 PM #3

Ah - I see the issue, haven't I?
In my case where the PSU is drawing 235W at the wall, that's not the actual load at the PSU output (like a 50% load), but rather closer to 200W (a drop from about 15% of 235W).
But the overall concept still makes sense, yes? An 85% efficiency means roughly a 15% loss?

_
_klearix_
Member
204
10-05-2016, 03:36 AM
#4
Correct. If the system draws 200w, the current at the wall would be 235w.
_
_klearix_
10-05-2016, 03:36 AM #4

Correct. If the system draws 200w, the current at the wall would be 235w.

K
Koollojoe
Posting Freak
830
10-05-2016, 09:56 AM
#5
you captured the main point correctly. take the material being removed from the wall and calculate the 80% or 85% as the PSU uses. remember, this isn't a fixed rule, but a helpful reference. it won't always hit exactly 10 or 15%, but it provides a solid estimate.
K
Koollojoe
10-05-2016, 09:56 AM #5

you captured the main point correctly. take the material being removed from the wall and calculate the 80% or 85% as the PSU uses. remember, this isn't a fixed rule, but a helpful reference. it won't always hit exactly 10 or 15%, but it provides a solid estimate.

Z
zamys
Senior Member
690
10-26-2016, 08:01 AM
#6
A psu will only supply the power it needs, not exceeding its maximum capacity.
Efficiency mainly concerns the heat produced or the electricity cost.
To lower the power consumption, focus on the parts that consume energy.
Typically, the cpu and gpu are the main contributors.
Z
zamys
10-26-2016, 08:01 AM #6

A psu will only supply the power it needs, not exceeding its maximum capacity.
Efficiency mainly concerns the heat produced or the electricity cost.
To lower the power consumption, focus on the parts that consume energy.
Typically, the cpu and gpu are the main contributors.