Ultra x-finity ult-xf500 power supply silentpcreview.com brain anoxia

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For a fuller understanding of ATX power supplies, please read the reference

Article power supply fundamentals recommended

Units. Those who seek source materials can find intel’s various PSU

Design guides at form


For a complete rundown of testing equipment and procedures, please refer to

SPCR’s PSU test platform

V.3. The testing system is a close simulation of a moderate airflow

Mid-tower PC optimized for low noise.

In the test rig, the ambient temperature of the PSU varies proportionately

With its output load, which is exactly the way it is in a real PC environment.

But there is the added benefit of a high power load tester which allows incremental

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Load testing all the way to full power for any non-industrial PC power supply.

Both fan noise and voltage are measured at various standard loads. It is, in

General, a very demanding test, as the operating ambient temperature of the

PSU often reaches 40 °C at full power. This is impossible to achieve

With an open test bench setup.

Great effort has been made to devise as realistic an operating

Environment for the PSU as possible, but the thermal and noise results obtained

Here still cannot be considered absolute. There are too many variables in pcs

And too many possible combinations of components for any single test environment

To provide infallible results. And there is always the bugaboo of sample variance.Brain anoxia

These results are akin to a resume, a few detailed photographs, and some short

Sound bites of someone you’ve never met. You’ll probably get a pretty good overall

Representation, but it is not quite the same as an extended meeting in person.

REAL SYSTEM POWER NEEDS: while our testing loads the PSU to full output

(even 600W!) in order to verify the manufacturer’s claims, real desktop

PCs simply do not require anywhere near this level of power. The most pertinent

Range of DC output power is between about 65W and 250W, because it is the power

Range where most systems will be working most of the time. To illustrate this

Point, we conducted system tests

To measure the maximum power draw that an actual system can draw

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Under worst-case conditions. Our most power hungry intel 670 (P4-3.8) processor

Rig with an nvidia 6800GT video card drew ~214W DC from the power supply under

Full load — well within the capabilities of any modern power supply. Please

Follow the link provided above to see the details. It is true that very elaborate

Systems with SLI could draw as much as another 100W, perhaps more, but the total

Still remains well under 400W in extrapolations of our real world measurements.

SPCR’s high fidelity sound

Recording system was used to create MP3 sound files of this PSU. As

With the setup for recording fans, the position of the mic was 3 from the exhaust

Vent at a 45° angle, outside the airflow turbulence area.Brain anoxia the photo below shows

The setup (a different PSU is being recorded). All other noise sources in the

Room were turned off while making the sound recordings.


It important to keep in mind that fan speed varies with temperature,

Not output load. A power supply generates more heat as output increases, but

Is not the only the only factor that affects fan speed. Ambient temperature

And case airflow have almost as much effect. Our test rig represents a challenging

Thermal situation for a power supply: A large portion of the heat generated

Inside the case must be exhausted through the power supply, which causes a corresponding

Increase in fan speed.

When examining thermal data, the most important indicator of cooling efficiency

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Is the difference between intake and exhaust. Because the heat

Generated in the PSU loader by the output of the PSU is always the same for

A given power level, the intake temperature should be roughly the same between

Different tests. The only external variable is the ambient room temperature.

The temperature of the exhaust air from the PSU is affected by several factors:

• intake temperature (determined by ambient temperature and power output level)

• efficiency of the PSU (how much heat it generates while producing the required


• the effectiveness of the PSU’s cooling system, which is comprised of:

• overall mechanical and airflow design

• size, shape and overall surface area of heatsinks

• fan(s) and fan speed control circuit

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The thermal rise in the power supply is really the only indicator

We have about all of the above. This is why the intake temperature is important:

It represents the ambient temperature around the power supply itself. Subtracting

The intake temperature from the exhaust temperature gives a reasonable gauge

Of the effectiveness of the power supply’s cooling system. This is the only

Temperature number that is comparable between different reviews, as it is unaffected

By the ambient temperature.

On to the test results…

Ambient conditions during testing were 22°C and 19 dba. AC input was 121V and

60 hz, measured at the outlet.


NOTE: the ambient room temperature during testing

Can vary a few degrees from review to review.Brain anoxia please take this into account

When comparing PSU test data.



In general, the voltage regulation was good enough, with all of the voltages

Running a little high. As expected, some of the lines dropped

Below the nominal voltage as the output increased, but none fell out of


The +3.3V rail, on the other hand, was a little too high for comfort; it drifted

Above the +5% tolerance defined by ATX12V when the total output load was below

100W. It should be stressed that this is probably an artifact of our specific

Sample; it is impossible to draw any conclusions about the line as a whole

Without seeing more samples.

2. EFFICIENCY was almost exactly what ultra claims: ~78% at 300W output,

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And ~73% at full load. As the graph on their web site claims, peak efficiency

Is sustained from through a range of about 150-300W. This is solid but unimpressive

Efficiency. Efficiency in the high 70’s is good performance, but many of ultra’s

Competitors manage to break 80% efficiency for at least one data point.

3. POWER FACTOR was typical of a unit with no power factor correction,

Between 0.57~0.68. At full load, the unit drew ~1,000VA from the wall, or a little

Over half of the capacity of a standard household circuit. This is within the

8.5A that ultra specifies as the maximum current draw at full load.


Cooling throughout most of the lower output range (where 99% of systems will

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Spend most of their time) was fairly good. But, as the output increased, the

Cooling increasingly struggled to keep pace with the heat being generated.

The fan reached maximum speed at around ~250W, and above

This level, cooling was not quite good enough. By the time the output level reached

500W, the temperature rise through the X-finity was a staggering 27°C —

Which suggests a level of cooling that compares some fanless units. Although

It sustained its full rated output for about 5 minutes, we are not sure that it

Could sustain this output level indefinitely; the cooling system does not seem good

Enough. We refrained from running the full load test much longer, what with the smells and the measured exhaust temperature.Brain anoxia keep in mind, the likelihood of any PC demanding 500W load long term is just about nil.


The noise character of the unidentified LED fan was not endearing.

The sound it made is typical of a ball-bearing fan: at low speeds

There was a buzz that refused to get any quieter, no matter how slow the fan

Was turning. This limited the noise floor to ~23 [email protected] — quiet, but not

That quiet.


Fan speed increased quickly once output reached 150W output and it reached full speed at a fairly low output level of 250W. The fan became

Noisy and bothersome almost as soon as it ramped up. It’s not clear whether the

Problem is the fan controller or simply the poor cooling at higher output levels,

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But this power supply is unlikely to be quiet except in low-power circumstances.

Another issue with the fan controller is its variability. While changing the

Load on the test bench, I discovered that I could provoke almost instantaneous

Changes in fan noise by toggling the 8A switch on the +5V line. The changes

Were often a volt or more, which translated into an instantly audible difference

Of several decibels. Given the highly variable nature of computing, it is quite

Likely that such sudden swings in power and noise could occur in an actual system.

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