ASUS Atlas A-45GA 450 W Power Supply Review
Load Tests
Contents
We conducted 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 load patterns, trying to pull around 20%, 40%, 60%, 80%, and 100% of its labeled maximum capacity (actual percentage used listed under “% Max Load”), watching how the reviewed unit behaved under each load. In the table below we list the load patterns we used and the results for each load.
If you add all the power listed for each test, you may find a different value than what is posted under “Total” below. Since each output can vary slightly (e.g., the +5 V output working at +5.10 V), the actual total amount of power being delivered is slightly different than the calculated value. On the “Total” row we are using the real amount of po
wer being delivered, as measured by our load tester.
The +12VA and +12VB inputs listed below are the two +12 V independent inputs from our load tester. During this test the +12VA input was connected to the power supply +12V1 and +12V2 rails, while +12VB was connected to the power supply +12V2 rail (ATX12V connector).
| Input | Test 1 | Test 2 | Test 3 | Test 4 | Test 5 |
| +12VA | 3 A (36 W) | 3.5 A (42 W) | 4.5 A (54 W) | 5.5 A (66 W) | 6.25 A (75 W) |
| +12VB | 2.5 A (30 W) | 3.25 A (39 W) | 4 A (48 W) | 5 A (60 W) | 6 A (72 W) |
| +5V | 1 A (5 W) | 1 A (5 W) | 1.5 A (7.5 A) | 1.5 A (7.5 A) | 2 A (10 W) |
| +3.3 V | 1 A (5 W) | 1 A (5 W) | 1.5 A (4.95 W) | 1.5 A (4.95 W) | 2 A (6.6 W) |
| +5VSB | 1 A (5 W) | 1 A (5 W) | 1 A (5 W) | 1 A (5 W) | 1 A (5 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 | 90.7 W | 99.8 W | 124.5 W | 147.9 W | 172.6 W |
| % Max Load | 20.2% | 22.2% | 27.7% | 32.9% | 38.4% |
| Room Temp. | 46.1° C | 44.3° C | 43.6° C | 42.5° C | 42.3° C |
| PSU Temp. | 48.0° C | 47.3° C | 47.0° C | 47.0° C | 47.1° C |
| Voltage Regulation | Pass | Pass | Pass | Pass | Pass |
| Ripple and Noise | Pass | Pass | Pass | Pass | Pass |
| AC Power | 122.4 W | 132.4 W | 162.8 W | 192.0 W | 223.4 W |
| Efficiency | 74.1% | 75.4% | 76.5% | 77.0% | 77.3% |
| AC Voltage | 113.4 V | 113.5 V | 113.1 V | 113.5 V | 114.0 V |
| Power Factor | 0.960 | 0.962 | 0.966 | 0.968 | 0.970 |
| Final Result | Pass | Pass | Pass | Pass | Pass |
| Input | Test 6 | Test 7 | Test 8 | Test 9 | Test 10 |
| +12VA | 7.5 A (90 W) | 8.25 A (99 W) | 9.25 A (111 W) | 10 A (120 W) | 11 A (132 W) |
| +12VB | 7 A (84 W) | 8 A (96 W) | 9 A (108 W) | 10 A (120 W) | 11 A (132 W) |
| +5V | 2 A (10 W) | 2.5 A (12.5 W) | 2.5 A (12.5 W) | 3 A (15 W) | 3 A (15 W) |
| +3.3 V | 2 A (6.6 W) | 2.5 A (8.25 W) | 2.5 A (8.25 W) | 3 A (9.9 W) | 3 A (9.9 W) |
| +5VSB | 1 A (5 W) | 1 A (5 W) | 1 A (5 W) | 1 A (5 W) | 1 A (5 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 | 199.4 W | 223.5 W | 246.5 W | 271.1 W | 295.4 W |
| % Max Load | 44.3% | 49.7% | 54.8% | 60.2% | 65.6% |
| Room Temp. | 42.5° C | 43.8° C | 45.1° C | 46.5° C | 48.5° C |
| PSU Temp. | 47.4° C | 48.0° C | 49.0° C | 50.2° C | 52.1° C |
| Voltage Regulation | Pass | Pass | Pass | Pass | Pass |
| Ripple and Noise | Pass | Pass | Pass | Pass | Pass |
| AC Power | 257.3 W | 290.3 W | 321.6 W | 355.1 W | 386.9 W |
| Efficiency | 77.5% | 77.0% | 76.6% | 76.3% | 76.4% |
| AC Voltage | 114.3 V | 113.1 V | 112.4 V | 112.4 V | 111.9 V |
| Power Factor | 0.971 | 0.972 | 0.973 | 0.973 | 0.974 |
| Final Result | Pass | Pass | Pass | Pass | Pass |
| Input | Test 11 | Test 12 | Test 13 |
| +12VA | 12 A (144 W) | 13 A (156 W) | 14 A (168 W) |
| +12VB | 11.75 A (141 W) | 12.75 A (153 W) | 13.5 A (162 W) |
| +5V | 3.5 A (17.5 W) | 3.5 A (17.5 W) | 4 A (20 W) |
| +3.3 V | 3.5 A (11.55 W) | 3.5 A (11.55 W) | 4 A (13.2 W) |
| +5VSB | 1 A (5 W) | 1 A (5 W) | 1 A (5 W) |
| -12 V | 0.5 A (6 W) | 0.5 A (6 W) | 0.5 A (6 W) |
| Total | 318.3 W | 341.0 W | 365.6 W |
| % Max Load | 70.7% | 75.8% | 81.2% |
| Room Temp. | 45.7° C | 46.7° C | 46.2° C |
| PSU Temp. | 50.3° C | 49.3° C | 46.7° C |
| Voltage Regulation | Pass | Pass | Pass |
| Ripple and Noise | Pass | Pass | Pass |
| AC Power | 421.8 W | 453.9 W | 489.4 W |
| Efficiency | 75.5% | 75.1% | 74.7% |
| AC Voltage | 112.2 V | 111.5 V | 111.8 V |
| Power Factor | 0.975 | 0.975 | 0.976 |
| Final Result | Pass | Pass | Pass |
The ASUS Atlas A-45GA 450 W can’t deliver its labeled power at high temperatures. The maximum we could pull from it was 365 W. Above that the unit would shut down, meaning that a protection kicked in. At least it won’t burn if you try to pull more than it is capable of delivering.
Efficiency was always below 80% (between 74.1% and 77.5%), proving that the presence of an active PFC circuit has nothing to do with efficiency.
Voltage regulation was the good news about this power supply: all voltages were always within 3% of their nominal values, including the -12 V output. This means that voltages were closer to their nominal values than required, since the ATX12V specification allows a 5% tolerance for the positive voltages and a 10% tolerance for the negative voltages.
Noise and ripple levels are another highlight of the product, always way below the maximum allowed, as you can see in the figures below. As we always point out, the limits are 120 mV for +12 V and -12 V outputs, and 50 mV for +5 V and +3.3 V outputs, and all numbers are peak-to-peak figures.
Figure 18: +12VA input from load tester at 365.6 W (39.2 mV)
Figure 19: +12VB input from load tester at 365.6 W (38.4 mV)
Figure 20: +5V rail with power supply delivering 365.6 W (13.4 mV)
Figure 21: +3.3 V rail with power supply delivering 365.6 W (12.8 mV)
I bought this power supply in 2009 and it never let me down. Will have to look for a more powerful one though, as I am contemplating buying a new graphics card