Foxconn FX-250T Power Supply
The bundled power supply is yet another difference between the RS-224 and RS-338(L). Although the form-factor (TFX), installation method and rated wattage are the same, the PSU is considerably different, both externally and in its specs.
The protrusion on the PSU’s case helps accommodate a fan with a standard thickness of 25 mm instead of the other model’s 15mm fan. The downside is that the PSU limits the dimensions of the cooling system on the expansion card.
It’s good that the Foxconn FX-250T has a wire fan grid instead of punched-out vents like in the other PSUs (except the InWin IP-AD160-2 with its exposed 40mm fan).
The outward part of the PSU has a standard honeycomb mesh and a 230/115V switch.
Having the same rated wattage as the Channel Well DSI250P (which was employed in the RS-224 computer case), the Foxconn FX-250T (its actual maker FSP is mentioned on the label, by the way) has a considerably lower load capacity of the +12V rail (168 compared to 216 watts) and a slightly lower load capacity of the +3.3V and +5V rails.
In fact, the real-life output power of this PSU is no higher than 200 watts since you can hardly load the +3.3V and +5V rails by more than 30 watts whatever components you may install.
The PSU is equipped with the following cables and connectors:
- One mainboard cable with a 24-pin connector (34 cm)
- One CPU cable with a 4-pin connector (32 cm)
- One cable with two PATA power connectors and a floppy-drive plug (34+15+15 cm)
- One cable with two SATA power connectors (34+15+15 cm)
We’ve got too many connectors here. We doubt that anyone would need two PATA power connectors in a modern compact PC. And if you’ve got an antique floppy drive, you will hardly be able to connect it due to the lack of space for a power connector between the floppy drive bay and the PSU.
Working together with our APC SmartUPS SC 620, the PSU could switch to the UPS’s batteries at loads up to 225 watts. You’ll see shortly why this load is so low despite the lack of active PFC.
The voltages are stable enough. +12V leaves the 5% range when there’s a low load on the +12V rail and a high load on the +3.3V and +5V rails whereas the +3.3V voltage does the same in the opposite situation. However, the voltages are not going to deflect by more than 3% from the required levels in the typical load range.
The high-frequency voltage ripple at full load is within the permissible range but the +5V and +12V voltages seem to fluctuate at a lower frequency as is indicated by the shape of their graphs.
The output voltage ripple at the double mains frequency is just awful. It is many times as strong as permitted by the industry standard. This must be the reason why the PSU was unable to switch to the UPS’s batteries at full load.
The ripple quickly weakens, however, as the load decreases, meeting the industry requirements at 215-220 watts. It is already very weak at a load of 200 watts (and we want to remind you that you can hardly get anything more from this PSU due to the low load capacity of its +12 rail).
The Foxconn FX-250T is quite efficient for a compact PSU: 84.2% at the maximum and above 80% at typical loads. It is only at loads above 200 watts (which are hardly possible in reality) and below 60 watts (like with most other PSUs) that the efficiency is lower.
The Foxconn FX-250T is rather ambiguous when it comes to noisiness. On one hand, it is only at a load of 100 watts that its fan reaches the start speed of the Antec FP-150-8’s fan. But its fan accelerates faster, reaching the Antec’s top speed at 130 watts and going higher up to 2950 RPM at 175 watts. And this speed is then maintained until full load.
Thus, the Foxconn RS-338(L) computer case is going to be quiet enough if stuffed with low-consumption components. But if the components need as much power as the bundled PSU can provide, the noise level will be uncomfortably high.
The standby source can provide its specified 2 amperes but without any reserve.
Overall, the Foxconn FX-250T PSU is efficient, quiet at moderate loads and stable. We can only criticize it for its overstated output power (we’d have no complaints about its electrical parameters if the real 200 watts were specified on its label instead of 250 watts), some outdated connectors (whose cables occupy valuable space), and high level of noise at high loads.