Antec Phantom 500w Silent PSU Page: 1

The balance between power and performance is a hard one to perfect. Cooling the most high-powered power supplies is a difficult task, and not something that is always possible with low noise fans.

Various 'Silent' Power supplies have been designed to try and combat this problem, incorporating fanless and watercooled designs. However, for the most part these units have been underpowered and incapable of producing stable voltage output.

Today I'll be looking at the Phantom 500w power supply from Antec. This unit is a hybrid design, which is passively cooled under light to moderate load, and powers on an integrated 80mm fan when things start to get really hot!


A short while ago I took a look and Antec's NeoHE 550w PSU, and commented on the professional styling of the packaging. Antec really don't need flashy, over the top packaging to make sales - their reputation for making quality products does a good enough job.

The same approach has been used with the Phantom PSU packaging, which has a dark theme and a picture of this rather unusual looking power supply printed on the front.

Antec Phantom 500w Box Antec Phantom 500w Box

Antec Phantom 500w Box Antec Phantom 500w Box

The top and front of the packaging is largely a blank canvas, being only populated by some images of the unit and some brief specifications.

Flip the packaging around and we can see that Antec have gone into much more detail on the back of the box, listing some of the units best features, such as: Hybrid design, temperature sensitive fan, ATX 12v 2.0 and gold plated connectors to name just a few.

Antec Phantom 500w Box Antec Phantom 500w Box

The Phantom is very well packaged between 2 layers of moulded styrofoam, which should do a good job of protect the unit against any heavy-handed delivery drivers.

Included in the package are the following items:

- Antec Phantom 500w Manual
- Mains cable
- 4x ATX case screws
- Antec Phantom 500w PSU

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The following information has been shamelessly copied from Antec's website:

* ATX12V version 2.01 compliant with 24-and-20-pin adapter connector with detachable 4-pin section for 20-pin for backward compatibility with older motherboards
* Dual +12V outputs, with dedicated circuits to isolate the CPU power line from peripherals.
* Hybrid fan design
* Exceptional power efficiency up to 85% (US version) at full load
* 4 Serial ATA power connectors
* PCI-E graphic card power connector
* Fanless operation for absolutely silent computing. Three user selectable fan kick-in points for quiet computing under higher loads: 40, 47.5, or 55 degrees C.
* Specially designed internal heatsinks and chassis heatsink for maximum heat dissipation
* ATX12V v2.0 compliance and ultra-high-efficiency design (up to 82%) allows Phantom to generate up to 70% less heat and consume 25% less power than standard PSU's saving you money on your electric bill
* Power Factor value greater than 90% (EU only)
* Gold plated connector for superior conductivity




Weighing in at 3.1kg, this is a very heavy unit for its size. Most of the weight comes from the massive surface area of aluminium fins that dissipate heat, helping to cool the unit.

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Having tested quite a few power supplies here at OC3D, I thought that I'd seen every imaginable style. However, the Antec Phantom is very different to the usual 'black box' or 'blinged-out' affair...

Antec Phantom 500w Top Antec Phantom 500w Back

To put it in simple terms, the Phantom is basically one large aluminium heatsink. The fins on the top and bottom of the unit allow for maximum heat dissipation, thus reducing the need for a high-powered fan. The back of the unit has a meshed grill that allows for hot air to be expelled out of your case when the fan is activated.

You will also notice that the Phantom 500w does not have a voltage selection switch. This is because the unit is able to detect the input voltage automatically and switch accordingly.

Antec Phantom 500w Side Antec Phantom 500w Front

The front of the Phantom is quite different to your usual power supply. Rather than opting for a boring metal fan grill, Antec have molded a very tasty looking plastic fascia to give the unit a bit of an 'mean' look.

Looking around the side of the unit we can see a small air ventilation grill which assists in providing fresh air to some of the hotter components contained inside. Fins also stretch the length of the unit, but seem to be for visual effect more than anything else.

Antec Phantom 500w Switch Antec Phantom 500w Light

Other features of the unit include the ability to set what temperature the internal 80mm fan is activated at (40-55°C) by means of a 3-way switch.

Antec have also included a very cool looking light strip that is illuminated when the unit is switched on. This is especially handy, as when the fan is not activated on the unit, it is impossible to know that the unit is switched on.

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It seems quite common for smaller power supplies not to be as well equipped in the connectors department as some of the larger units. With this in mind, lets take a look at the Phantom 500w...

Antec Phantom Cables Antec Phantom Cables

Antec Phantom Cables Antec Phantom Cables

It's a shame to see that Antec didn't decide to sleeve all of the cables on the Phantom 500w unit. Sleeving not only improves the appearance, but also helps to increase the air flow around the inside of your case by keeping cables closely bound together. Thankfully Antec did sleeve the ATX connector cable which is by far the biggest and most bulky of cables of all connectors on an ATX PSU.

Antec Phantom Cables Antec Phantom Cables

In order to maintain compatibility with older motherboards whilst still natively supporting the latest ones, Antec have adopted both 8-Pin EPS and 4-Pin ATX-12v standards. This has been done by "piggy-backing" the 4-pin connector off the back of the 8-pin connector.

As with many other modern Power Supplies, the ATX connector can be split or joined together to form either a 20-Pin or 24-Pin connector.


SATA Molex Floppy

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Looking Inside

As we've already seen, the Phantom 500w is very different in design to any other power supply on the market from the outside, but how about the inside? Lets take a look...

Antec Phantom 500w Inside Antec Phantom 500w Inside

Looking inside the Phantom, we can see that components of reasonable size and quality have been used. All components that produce heat have been fitted with aluminium heatsinks to keep the unit cool and help maintain its efficiency.

During my inspection of the unit I was unable to find any adjustable potentiometers, which could have potentially been use to adjust the rail voltages.

Antec Phantom 500w Heatsink Antec Phantom 500w Heatsink

As we can see from above, heat is transferred from the heatsinks and other components to the large surface area of the aluminium casing by thermal tape. This maximises the cooling potential rather than relying on air to transfer the heat into the casing.

Antec Phantom 500w Fan Antec Phantom 500w Fan

As previously mentioned, the Phantom is a hybrid design. This means that under idle and 'light load' conditions, the Phantom relies on passive cooling to keep the components cool. However, under heavy load conditions, the Phantom utilises an 80mm fan manufactured by XFan to prevent the unit from overheating.

The fan spins at 2500rpm, producing an airflow of 26.01cfm and a noise level of 27.08dBA. This would seem to be a very good choice of fan for a unit designed to be quiet, and we'll be testing this on the next page...

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Load testing

In order for the results from all current and future PSU reviews to remain fair and comparable, Overclock3D uses a custom built Power Supply load stress tester.

The tester will be placing the following loads on each of the Phantom's rails:

+3.3v - 20a Load
+5.0v - 20a Load
+12v1 - 10a Load
+12v2 - 10a Load

The results are collected from a Mastech MAS-345 Multimeter which logs its readings via RS232 to a PC.

Antec Phantom 3.3v Antec Phantom 5v

Very little fluctuation was observed on the +3.3v rail of the Phantom, with voltages only dipping by 0.07v when under load. However, the +5v rail suffered from quite a bit more fluctuation with the voltages dropping to 4.76v. While this quite low it still remains just within ATX specifications.

Antec Phantom 500w 12v1 Antec Phantom 500w 12v2

Both of the +12v rails on the Phantom produced the same idle and load results in our testing. Dropping to 11.93v when placed under heavy load, the results were somewhat average for this type of unit.

Efficiency Testing

Efficiency tests are performed by measuring the wattage consumed by the power supply at the mains against the power (in watts) consumed by the OC3D power supply stress tester.

The results may not be as accurate as those produced by professional testing equipment, but will certainly come in handy when comparing several power supplies against each other.

Antec Phantom 500w Efficiency

The Antec Phantom 500w was placed under a load of 406 watts. This counts for a total of 81% of the power supplies rated output. At this load, the power supply required 476 watts from the mains to produce the 406 watts required by our custom made power supply tester.

Therefore the efficiency of this power supply can be found by a simple equation: (406 / 476) * 100 that works out to be an efficiency rating of 85.2%.

Noise Testing

At present Overclock3D doesn't have the professional equipment required to reliably measure the noise output of devices. However, as a new part of our testing procedure we will be recording the PSU at idle and load so that you can make your own judgments. All recordings are taken at 30cm distance from the unit.

Idle Recording - Not required. Unit makes no noise!
Load Recording - Download

At idle the Phantom made no noise at all! This is due to passive cooling utilised by the unit working effectively.

After around 10 minutes under full load, the Phantom powered up the 80mm fan to deal with the increasing temperatures. The fan appeared to run at 100% speed throughout, but was never noisy or intrusive. With the Phantom 500w installed inside a case I was once again unable to hear the unit!

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The Antec Phantom 500w is by far the quietest power supply I've ever tested at Overclock3D. Even under heavy load conditions with the fan in use, the unit remained whisper quiet. I would certainly have no reservations in recommending this to people looking for silent power solutions for their HTPC or silent systems.

This great feature is only let down slightly by the below average performance of the units +5v rail and mediocre performance of the dual +12v rails. That said, many users of the Phantom are unlikely to fully load the power supply in the same way as our stress tester when combining the Phantom with a silent/HTPC system.

Retailing for £111.99 over at SpecialTech, this unit is by no means cheap for a 500w power supply, but I guess it all comes down to how much you value silence!

+ Quiet as a dead mouse
+ Great looks
+ Innovative cooling design
+ Great efficiency (85%)

- Majority of cables not sleeved
- Low performance on +5v rail
- Expensive for 500w


Thanks to Antec for providing this unit for review.

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