Xigmatek NRP-MC651 PSU, 50% load |
Voltage Line |
Power load (A) |
Minimum (V) |
Maximum (V) |
Delta (V) |
3.3V |
6 |
3.339 |
3.341 |
0.002 |
5V |
10 |
4.962 |
4.971 |
0.009 |
12V1 |
7 |
12.259 |
12.263 |
0.004 |
12V2 |
6 |
12.301 |
12.312 |
0.011 |
12V3 |
4 |
12.227 |
12.233 |
0.006 |
12V4 |
4 |
12.238 |
12.246 |
0.008 |
Xigmatek NRP-MC651 PSU, 75% load |
Voltage Line |
Power load (A) |
Minimum (V) |
Maximum (V) |
Delta (V) |
3.3V |
12 |
3.334 |
3.337 |
0.003 |
5V |
10 |
4.931 |
4.952 |
0.021 |
12V1 |
10 |
12.246 |
12.252 |
0.006 |
12V2 |
9 |
12.982 |
12.990 |
0.008 |
12V3 |
7 |
12.201 |
12.213 |
0.012 |
12V4 |
7 |
12.195 |
12.209 |
0.014 |
Xigmatek NRP-MC651 PSU, 100% load |
Voltage Line |
Power load (A) |
Minimum (V) |
Maximum (V) |
Delta (V) |
3.3V |
18 |
3.333 |
3.335 |
0.002 |
5V |
20 |
4.892 |
4.914 |
0.022 |
12V1 |
13 |
12.239 |
12.248 |
0.009 |
12V2 |
12 |
12.979 |
12.985 |
0.006 |
12V3 |
10 |
12.196 |
12.208 |
0.012 |
12V4 |
10 |
12.184 |
12.199 |
0.015 |
Xigmatek NRP-MC651 PSU, 30-100% Load Voltage Regulation Test
|
|
 |
3V |
5V |
12V1 |
 |
 |
 |
12V2 |
12V3 |
12V4 |
Xigmatek NRP-MC651 PSU, Efficiency Graph
| Power load |
30% |
40% |
50% |
60% |
70% |
80% |
90% |
100% |
| Efficiency |
82% |
84% |
85% |
84% |
82% |
82% |
81% |
80% |
Xigmatek NRP-MC651 PSU, Thermal Performance
Load (%) |
25% |
50% |
75% |
100% |
Intake temperature (Celsius) |
21.4 |
25.9 |
30.1 |
31.2 |
Exhaust temperature (Celsius) |
24.2 |
29.7 |
34.5 |
37.3 |
Temperature Delta (Celsius) |
2.8 |
3.8 |
4.4 |
6.1 |
The electrical performance of the Xigmatek NRP-MC651 is very good overall. The voltage regulation circuit keeps the 12V rails very stable and appears to be highly responsive, but it could be improved when it comes to the 5V line. Even though the 650W appears to be a little less efficient than its more powerful 850W version, it still reaches a peak efficiency of 85% at typical load and doesn't drop below 80% at maximum load.
Those who enjoy cool running PSUs will certainly love the NRP-MC651. With a temperature delta of just 6.1 Celsius at maximum load it certainly is one of the coolest running PSUs we have ever seen. On the other hand, the sensitive thermal controller of the fan is responsible for the great thermal performance of the unit. The fan will spin up very quickly as the load increases, trying to keep the product as cool as possible. Because of that this PSU is silent only up to 50-55% load; at 60% load the fan can be easily heard. And at heavy load (above 80%) the fan is loud.
