Contents
Shaw P4-S860V
Shaw is a brand that nobody seems to know much about, but rumor has it that they are an in-house brand for an Australian computer retailer called MSY, and that they are re-branded A-Power products. A-Power are a bit more well known, but for all the wrong reasons, so I’m pretty shaw this unit isn’t going to do well.
_
Considering that this model is available from MSY for only $27, I find it hard to believe that it would really have two 12V rails, so I opened it prematurely to find out and sure enough, it’s a single rail unit.
Load Testing
Test 1 (119.82W Load – Cold)
| Rail | Load | Voltage | Ripple |
| 12V | 4.93A | 12.33V | 13.8mV |
| 5V | 5.06A | 5.06V | 7.0mV |
| 3.3V | 10.06A | 3.32V | 9.0mV |
| −12V | 0A | −12.13V | 7.2mV |
| 5Vsb | 0A | 5.12V | 8.0mV |
| AC Power | 146.67W | ||
| Efficiency | 81.69% | ||
| Power Factor | 0.63 | ||
Test 2 (204.64W Load – Cold)
| Rail | Load | Voltage | Ripple |
| 12V | 9.83A | 12.29V | 23.6mV |
| 5V | 10.06A | 5.03V | 12.0mV |
| 3.3V | 10.03A | 3.31V | 7.2mV |
| −12V | 0.1A | −12.14V | 32.6mV |
| 5Vsb | 1.02A | 5.09V | 6.2mV |
| AC Power | 250.39W | ||
| Efficiency | 81.73% | ||
| Power Factor | 0.62 | ||
Test 3 (261.94W Load – Cold)
| Rail | Load | Voltage | Ripple |
| 12V | 14.6A | 12.17V | 33.4mV |
| 5V | 10.08A | 5.04V | 17.0mV |
| 3.3V | 10.06A | 3.32V | 8.2mV |
| −12V | 0.1A | −12.31V | 46.0mV |
| 5Vsb | 1.02A | 5.09V | 7.0mV |
| AC Power | 322.39W | ||
| Efficiency | 81.25% | ||
| Power Factor | 0.62 | ||
Test 4 (314.63W Load – Cold)
| Rail | Load | Voltage | Ripple |
| 12V | 19.18A | 11.99V | 40.4mV |
| 5V | 10.17A | 5.07V | 21.2mV |
| 3.3V | 10.03A | 3.31V | 8.2mV |
| −12V | 0.1A | −12.46V | 59.2mV |
| 5Vsb | 1.02A | 5.09V | 7.6mV |
| AC Power | 391.4W | ||
| Efficiency | 80.38% | ||
| Power Factor | 0.62 | ||
Test 5 (368.93W Load – Cold)
| Rail | Load | Voltage | Ripple |
| 12V | 21.67A | 12.04V | 59.2mV |
| 5V | 15.0A | 5.00V | 28.6mV |
| 3.3V | 10.0A | 3.30V | 8.6mV |
| −12V | 0.11A | −12.82V | 80.2mV |
| 5Vsb | 1.02A | 5.08V | 8.2mV |
| AC Power | 477.92W | ||
| Efficiency | 77.20% | ||
| Power Factor | 0.61 | ||
Test 6 (419.92W Load – Cold)
| Rail | Load | Voltage | Ripple |
| 12V | 26.16A | 11.89V | ? |
| 5V | 15.09A | 5.03V | ? |
| 3.3V | 10.0A | 3.30V | ? |
| −12V | 0.11A | −13.05V | ? |
| 5Vsb | 1.02A | 5.08V | ? |
| AC Power | 584.01W | ||
| Efficiency | 71.90% | ||
| Power Factor | 0.62 | ||
This power supply did a lot better than the Sun Pro and Excel, but it’s still far from perfect. The Shaw’s main strength was its voltage regulation, managing 2.8% on the 12V rail, 1.4% on the 5V, and an excellent 0.6% on the 3.3V rail. The ripple suppression on the 3.3V and 5Vsb rails was also very good, with neither rail exceeding 10mV at any time. The ripple suppression on the other rails, though, was unremarkable. Yes, it was in spec, but I really would like to see the ripple stay below half the maximum allowed, which didn’t happen. The real let-down, though, was the efficiency. It peaked during Test 2, at just under 82%. On 230V, this is quite poor. During Test 6, at just under 50% load, the efficiency nose-dived to just under 72%, and the power supply ran just long enough for me to read the voltages. The switching transistors exploded before I could read the ripple, which is why there are question marks in the ripple column of the table.
| Rail | Test 4 (314.63W) | Test 5 (368.93W) |
| 12V |  |
 |
| 5V |  |
 |
| 3.3V |  |
 |
| −12V |  |
 |
| 5Vsb |  |
 |
A Look Inside
_
Starting as usual at the input filtering, the Shaw has two X capacitors, two common-mode chokes and five Y-Capacitors (including the one after the rectifier), but there are no MOVs. The switching transistors are STWH13009s, rated at 12A. They were clearly nowhere near enough to allow this unit to deliver 860W. After removing them from the heat sink, the damage to them was extensive. One had a hole blown through the back and had started to melt the heat sink behind it. The primary capacitors are 680µF parts from Canicon, an infamously poor quality manufacturer.
Moving on to the secondary side, the 12V rail’s rectifier is an MBR20100CT. Although I couldn’t identify the manufacturer, the part number suggests its a 20A part. The label says that the 12V rail is supposed to be capable of 54A (28A + 26A), so this part is insufficient. The 5V rail uses an STPS3045CW rectifier rated at 30A, while the 3.3V rail uses an SB2040CT rectifier. Again, I couldn’t positively identify the manufacturer, but the part number suggests it’s a 20A part. The capacitors used are a mix of ChengX and Ricon brand. The reliability of both of these brands is questionable.
_
Now why didn’t Super Fan come and save the switchers from overheating? Superman jokes aside, the fans did stay very quiet throughout the testing.
Specifications and Conclusions
| Real Wattage | 370W |
| OEM | Unknown |
| PFC | None |
| Price | $27 AUD (from MSY) |
| ATX Connector type | 20+4 pin |
| Worst-case voltage regulation (12v, 5v, 3.3v) | 2.8%, 1.4%, 0.6% |
| Worst-case ripple (12v, 5v, 3.3v) | 59.2mV, 28.6mV, 8.6mV |
| Worst-case efficiency | 77.2% |
| Input filtering | Adequate |
| CPU Connector | ATX12v (4 pin) |
| PCIe Connectors | 1x 6 pin |
| Molex (Peripheral) Connectors | 2 |
| FDD Power connectors | 1 |
| SATA Power connectors | 6 |
Pros: Good voltage regulation, Quiet
Cons: Can’t even deliver half its labelled rating, Low quality fan and capacitors, Inefficient
Score: 3/10
Loading ...