Athena Power 350W FlexATX Power Supply Review (AP-MFATX35)

1. Introduction2. Athena Power 350W FlexATX 3. Testing Methodology and Results4. Closing Thoughts5. View All Pages

If you are in the market for a 1U Mini ITX server power supply then today's product will be of interest. The Athena Power 350W FlexATX supply is designed to provide compact flexibility for mini servers. It is also compatible with many Shuttle XPC, HP Pavilion and IBM SurePOS systems.

The Athena Power 350W FlexATX power supply is 80 Plus Bronze Certified and it features an Active PFC (Power Factor Correction) and remote ON/OFF function for high efficiency and reliability. It is cooled by a 40mm ball bearing fan and has thermal fan speed control to ensure noise levels are reduced when possible.

Output Power	350 Watt
Input Voltage	88 -264 Volts Ac
Frequency	60 / 50 Hz
Weight	2 lbs
Temperature Range	Operating: 0°C ~ +50°C on Full Load; Storage & Shipping: -20°C ~ +80°C
Humidity	5 ~ 90% on Operating, 5 ~ 95% on Storage
Dielectric Withstand	Primary Frame Ground 1800V AC for 1 Second
MTBF	100,000 Hours on Maximum Load at +25°C
Rise time	Less than 20ms
Hold-up Time	17ms Minimum at Nominal Input Voltage
Dimensions	( W x H x D ) 3.2″ x 1.7″ x 6″
Output	Voltage +5V -5V +12V1 +12V2 -12V +3.3V +5V-SB Current 15A 0.5A 11A 11A 0.8A 15A 3.0A
Certification	FCC, UR, CB, CE, Rohs,
Warranty	3 Year  Manufacture Limited

The Athena Power 350W FlexATX is supplied in a plain, small white box with blue accenting. There are brief specifications listed on the front and a sticker top left which highlights the power output.

There is no bundle, just a power cable and the supply itself.

The unit is built to the demands of this specific audience. Basically as bare bones in appearance as you will get. There is a small 40mm fan on the rear, next to the power connector.

CONNECTORS

ATX Connector 24 (20+4) Pin P4-12V 4 Pin PCIE 6 Pin SATA 15 Pin Molex 4 Pin Floppy 4 Pin

The combined power of the 3.3V+5V output is 120Watt, and the +12V1 and 12V2 output can handle 11A each.

The Active PFC internal design is clean with high grade 105c rated components used in the design. There are several heatsinks in key positions, and these have sensors attached to help ensure the 40mm fan delivers enough air flow.

Additional technical assistance: Peter McFarland and Jeremy Price.

Correctly testing power supplies is a complex procedure and KitGuru have configured a test bench which can deliver up to a 2,000 watt DC load. Due to public requests we have changed our temperature settings recently – previously we rated with ambient temperatures at 25C, we have increased ambient temperatures by 10c (to 35c) in our environment to greater reflect warmer internal chassis conditions.

We use combinations of the following hardware:
• SunMoon SM-268
•  CSI3710A Programmable DC load (+3.3V and +5V outputs)
•  CSI3711A Programmable DC load (+12V1, +12V2, +12V3, and +12V4)
• Extech Power Analyzer
• Extech MultiMaster MM570 digital multimeter
• Extech digital sound level meter
• Digital oscilloscope (20M S/s with 12 Bit ADC)
• Variable Autotransformer, 1.4 KVA

DC Output Load Regulation
Combined DC Load	+3.3V		+5V		+12V		+5VSB		-12V
	A	V	A	V	A	V	A	V	A	V
88W	3.75	3.33	4.02	4.99	4.21	12.07	0.60	4.99	0.12	-12.04
176W	7.52	3.31	8.03	4.99	8.51	12.02	1.22	4.97	0.25	-12.05
263W	11.26	3.30	12.02	4.98	12.76	11.95	1.86	4.94	0.37	-12.07
350W	15.02	3.26	16.01	4.95	16.98	11.89	2.51	4.91	0.50	-12.11

Athena Power 350W	Maximum Load
	354W

Load regulation is pretty good across the output range. We only managed to get an extra 4 Watts from the power supply before it would switch off.

We then used an oscilloscope to measure AC ripple and noise present on the DC outputs. We set the oscilloscope time base to check for AC ripple at both high and low ends of the spectrum.

ATX12V V2.2 specification for DC output ripple and noise is defined in the ATX 12V power supply design guide.

ATX12V Ver 2.2 Noise/Ripple Tolerance
Output	Ripple (mV p-p)
+3.3V	50
+5V	50
+12V1	120
+12V2	120
-12V	120
+5VSB	50

Obviously when measuring AC noise and ripple on the DC outputs the cleaner (less recorded) means we have a better end result. We measured this AC signal amplitude to see how closely the Athena Power unit complied with the ATX standard.

AC Ripple (mV p-p)
DC Load	+3.3V	+5V	+12V	5VSB
88W	15	10	20	15
176W	15	15	35	15
263W	20	15	50	20
350W	25	20	60	25

Ripple suppression is well within the guidelines, although it is noticeable across all outputs.

Efficiency (%)
88W	81.56
176W	84.67
263W	82.12
350W	80.23

Efficiency is decent, although it did fall a little short of 80 Plus Bronze specifications.

We take the issue of noise very seriously at KitGuru and this is why we have built a special home brew system as a reference point when we test noise levels of various components. Why do this? Well this means we can eliminate secondary noise pollution in the test room and concentrate on components we are testing. It also brings us slightly closer to industry standards, such as DIN 45635.

Today to test the Corsair Power Supply we have taken it into our acoustics room environment and have set our Digital Sound Level Noise Decibel Meter Style 2 one meter away from the unit. We have no other fans running so we can effectively measure just the noise from the unit itself.

As this can be a little confusing for people, here are various dBa ratings in with real world situations to help describe the various levels.

KitGuru noise guide
10dBA – Normal Breathing/Rustling Leaves
20-25dBA – Whisper
30dBA – High Quality Computer fan
40dBA – A Bubbling Brook, or a Refridgerator
50dBA – Normal Conversation
60dBA – Laughter
70dBA – Vacuum Cleaner or Hairdryer
80dBA – City Traffic or a Garbage Disposal
90dBA – Motorcycle or Lawnmower
100dBA – MP3 player at maximum output
110dBA – Orchestra
120dBA – Front row rock concert/Jet Engine
130dBA – Threshold of Pain
140dBA – Military Jet takeoff/Gunshot (close range)
160dBA – Instant Perforation of eardrum

Noise (dBA)
88W	29.8
176W	31.7
263W	33.5
350W	34.8

With such a small fan there are always going to be compromises and at full load, the Athena Power 350W FlexATX is clearly audible. It isn't realistic to be running this at full load on a continual basis and at 50% load it is audible, but not really noticeable especially in a server style environment.

Temperature (c)
	Intake	Exhaust
88W	35	37
176W	38	42
263W	43	48
350W	47	58

Internal temperatures rise to an 11c above ambient variable under full load, which considering the compressed physical layout, is very acceptable.

The Athena Power 350W FlexATX is certainly a change of pace for Kitguru, because we don't often review power supplies designed for 1U Mini ITX Chassis.

As an overall product design it will certainly be a worthwhile purchase for the intended audience. That said, on a technical level it doesn't really excel in any key area. Ripple suppression falls within rated parameters, but it isn't the cleanest design we have tested, by a long shot. With such a small fan it can also get noisy in the upper 20% of power output.

Efficiency also fell a little short of 80 Plus Bronze levels of certification, but it may have been this particular sample. It certainly wasn't a bad result falling at 84.67% at 50% load and 80.24% at full load, but nonetheless a little disappointing. On a more positive note, load regulation was fairly good and indicate a decent design.

As a somewhat niche oriented power supply, the cost is a little higher than many people would expect – Newegg are selling it for $85 in the US and the expected price in the UK will be around £55 inc vat.

Pros:

• a solid design for the Mini ITX audience
• stable

Cons:

• doesn't really excel at anything
• can get loud at higher load

KitGuru says: if you have a specific demand for one of these units, then this is a decent purchase.

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