BFG ES-800 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 ta
ble 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 power being delivered, as measured by our load tester.
The +12V1 and +12V2 inputs listed below are the two +12 V independent inputs from our load tester and during all tests +12V1 input was connected to the power supply +12V1 and +12V3 rails and +12V2 input was connected to the power supply +12V2 rail.
| Input | Test 1 | Test 2 | Test 3 | Test 4 | Test 5 |
| +12V1 | 5.5 A (66 W) | 12 A (144 W) | 18 A (216 W) | 25 A (300 W) | 33 A (396 W) |
| +12V2 | 5.5 A (66 W) | 11 A (132 W) | 17 A (204 W) | 22 A (264 W) | 25 A (300 W) |
| +5V | 2 A (10 W) | 4 A (20 W) | 6 A (30 W) | 8 A (40 W) | 10 A (50 W) |
| +3.3 V | 2 A (6.6 W) | 4 A (13.2 W) | 6 A (19.8 W) | 8 A (26.4 W) | 10 A (33 W) |
| +5VSB | 1 A (5 W) | 1.5 A (7.5 W) | 2 A (10 W) | 2.5 A (12.5 W) | 3 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 | 159.8 W | 321.1 W | 482.3 W | 632.1 W | 779.6 W |
| % Max Load | 20.0% | 40.1% | 60.3% | 79.0% | 97.5% |
| Room Temp. | 48.6° C | 49.8° C | 50.6° C | 47.4° C | 50.8° C |
| PSU Temp. | 48.2° C | 52.6° C | 54.6° C | 55.1° C | 51.8° C |
| Voltage Stability | Pass | Pass | Pass | Pass | Pass |
| Ripple and Noise | Failed on -12 V | Pass | Failed on +5VSB | Failed on +5VSB | Failed on +5 V, +3.3 V and +5VSB |
| AC Power | 189.1 W | 377.0 W | 572.8 W | 767.0 W | 985.0 W |
| Efficiency | 84.5% | 85.2% | 84.2% | 82.4% | 79.1% |
| AC Voltage | 110.9 V | 110.2 V | 108.9 V | 105.6 V | 103.4 V |
| Power Factor | 0.995 | 0.986 | 0.989 | 0.991 | 0.989 |
| Final Result | Pass | Pass | Pass | Pass | Fail |
BFG ES-800 presents a high efficiency between 84% and 85% if you pull up to 60% of its labeled capacity (i.e., up to 480 W). Pulling 80% from its maximum wattage efficiency dropped to 82.4%, still above 80%. At full load, however, efficiency dropped to 79.1%. Important to notice that we tested this power supply with our new GWInstek precision power meter.
The main problem with this power supply is noise and ripple. The first sample we got presented noise levels outside specs from test two on, with -12 V at 195 mV during test one but at 50 mV or below on other tests. For example, the +5 V output presented a noise level between 67.2 mV and 121 mV, depending on the load and +3.3 V output presented noise level between 64.4 mV and 133 mV, also depending on the load. The maximum allowed for these two outputs is 50 mV (all values are peak-to-peak). The standby output (+5VSB) was also out of range from test three on (between 64 mV and 96.8 mV).
We got in touch with BFG and they said they were aware of the problem and it would affect only the first batch of ES-800, models with serial number starting with 0804. They sent us a second sample, which would supposedly have this problem fixed, serial number starting with 0835. The results above are from this second “fixed” sample.
This second sample fixed the noise problem at +3.3 V and +5 V, at least partially. We only saw it out of range during test number five, where noise level at +3.3 V was at 68.4 mV and at +5 V was at 61.4 mV. During test four noise on these two outputs was at 48.4 mV and 45.2 mV, almost touching the maximum allowed. On the other hand, with the second sample we saw exactly the same problem with the -12 V output during test one (172 mV noise level) and +5VSB during tests three through five (between 64.2 mV and 115.4 mV).
ES-800 can really deliver 800 W at 50° C, but as we always mention, power isn’t everything.
Figure 18: +3.3 V during test five with the first sample (0804 batch), 133 mV.
Figure 19: +3.3 V during test five with the second sample (0835 batch), 68.4 mV.
Figure 20: +5 V during test five with the first sample (0804 batch), 121 mV.
Figure 21: +5 V during test five with the second sample (0835 batch), 61.4 mV.
Figure 22: +12V1 input from load tester during test five with the second sample (0835 batch), 43.2 mV.
Figure 23: +12V2 input from load tester during test five with the second sample (0835 batch), 44.2 mV.
Now let’s see if we could pull more than 800 W from this unit.