We made several tests with this power supply as described in the article Hardware Secrets Power Supply Test Methodology.
First we tested this power supply with five different loads patterns, trying to pull around 20%, 40%, 60%, 80% and 100% of its labeled maximum capacity (under “% Max Load” we list the actual percentage that was used), watching how the reviewed unit behaved under each load. On the table below we list the load patterns we used and the results for each load.
We connected the two ATX12V connectors from this power supply to the +12V2 input from our load tester. This means that this input was connected to the +12V1 and +12V2 rails from the power supply. All other plugs were connected to the +12V1 input from our load tester, meaning that this input was connected to the +12V3 and +12V4 rails from the power supply.
If you add all the powers listed for each test you may find a value different from what posted under “Total” below. Since each output can have a slight variation (e.g. +5 V output working at 5.10 V) the actual total amount of power being delivered is slightly different from the calculated value. On “Total” row we are using the real amount of power being delivered, as measured by our load tester.
Input | Test 1 | Test 2 | Test 3 | Test 4 | Test 5 |
+12V1 | 4 A (48 W) | 9 A (108 W) | 13 A (156 W) | 17.5 A (210 W) | 21.5 A (258 W) |
+12V2 | 4 A (48 W) | 9 A (108 W) | 13 A (156 W) | 17.5 A (210 W) | 21.5 A (258 W) |
+5 V | 1 A (5 W) | 2 A (10 W) | 4 A (20 W) | 6 A (30 W) | 8 A (40 W) |
+3.3 V | 1 A (3.3 W) | 2 A (6.6 W) | 4 A (13.2 W) | 6 A (19.8 W) | 8 A (26.4 W) |
+5VSB | 1 A (5 W) | 1 A (5 W) | 1.5 A (7.5 W) | 2 A (10 W) | 2 A (15 W) |
| -12 V | 0.5 A (6 W) | 0.5 A (6 W) | 0.5 A (6 W) | 0.5 A (6 W) | 0.5 A (6 W) |
Total | 117.1 W | 246.6 W | 362.3 W | 489.2 W | 604.9 W |
% Max Load | 19.5% | 41.1% | 60.4% | 81.5% | 100.8% |
Room Temp. | 45.3º C | 43.6º C | 45.9º C | 45.9º C | 48.6º C |
PSU Temp. | 49.2º C | 47.5º C | 50º C | 49.4º C | 53.6º C |
Result | Pass | Pass | Pass | Pass | Pass |
Voltage Stability | Pass | Pass | Pass | Pass | Pass |
Ripple and Noise | Pass | Pass | Pass | Pass | Pass |
AC Power | 138 W | 284 W | 423 W | 584 W | 749 W |
Efficiency | 84.9% | 86.8% | 85.7% | 83.8% | 80.8% |
OCZ StealthXStream 600 W can really deliver its labeled power at 48º C, keeping efficiency always above 80%. With loads up to 80% (480 W) this power supply presented efficiency of at least 83% and with loads up to 60% (360 W) it kept efficiency around 85%, which is great. These results are very good, but of course we would like to see a higher efficiency when the power supply delivered its full 600 W to keep the great results achieved on lighter loads.
Voltage regulation during all our tests (including the overload tests we will present on next page) was outstanding, with all outputs within 3% of their nominal voltages – ATX specification defines that all outputs must be within 5% of their nominal voltages – except on -12 V under tests four, five and overload (next page), which was between -12.38 V and -12.47 V. These numbers, however, are still below 5% of the nominal voltage and inside the 10% margin that is set by the ATX spec for this output. Of course we always want to see values closer to the nominal voltage.
Noise and ripple was higher than competing products, but still inside ATX specs and not high enough to be considered a problem. When we were pulling 600 W from this power supply noise level at +12V1 input from our load tester was at 74 mV, at +12V2 input from our load tester was at 64.6 mV, at +5 V was 25.4 mV and at +3.3 V was 39.4 mV, as you can see on the screenshots below (just to remember, the maximum allowed values are 120 mV for +12 V and 50 mV for +5 V and +3.3 V; all these values are peak-to-peak values).
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Figure 15: Noise level at +12V1 input from our load tester with power supply delivering 600 W.
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Figure 16: Noise level at +12V2 input from our load tester with power supply delivering 600 W.
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Figure 17: Noise level at +5 V with power supply delivering 600 W.
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Figure 18: Noise level at +3.3 V with power supply delivering 600 W.
Let’s now see if we could pull more power from this product.
