1. Introduction2. The XFX Pro Series 450W PSU3. The XFX Pro Series 550W PSU4. The XFX Pro Series 450W PSU (Inside)5. The XFX Pro Series 550W PSU (Inside)6. XFX Pro Series 450W: Testing Methodology and Results7. XFX Pro Series 550W: Testing Methodology and Results8. Closing Thoughts9. View All Pages

Last year KitGuru reviewed all three of the new XFX Pro Series family, the 850W, the 750W and the 650W. We found them all to be great power supplies capable of solid power delivery at very competitive prices. Today we review the two latest members of the Pro Series family, the 450W and 550W units.

The XFX Pro Series 450W and 550W supplies are released to target the mainstream audience. Those people who don't demand high levels of power output. These would also be ideal as a low cost supply for a quality media center.

Both supplies are 80 Plus Bronze Certified units with rated efficiency of 85%, meaning that only 15% of the power drawn from the outlet is lost. XFX are also keen to highlight that some manufacturers are misleading the public with dubious, inflated wattage ratings.

EasyRail Technology is a key focal point for XFX with a slogan of ‘one rail, one setup’. We know that Seasonic are the manufacturer behind this design so we have high hopes for a quality power supply today. XFX are giving a full five year warranty with each power supply. European customers simply have to register their product on www.xfxforce.co.uk to upgrade the standard 3 year warranty to the full 5 year plan.

XFX packaging is always very stylish and the Pro 450W box uses identical artwork to other units in this range.

Inside are 4 mounting screws and two power cables, one for the European market and the other for the UK market. They also supply a well written manual with a basic overview of the 450w and 550w power supplies.

The supply is encased in soft foam for added shipping protection. As this is not a modular design all the cables emerge from the chassis and are wrapped with a heavy duty cable tie.

The XFX Pro 450W power supply is attractively designed with the name of the product on the sides and a large 120mm fan which takes centerstage at the top. The XFX paintwork is a matt finish which doesn't mark easily and maintains a clean looking appearance, even after rough handling.

The front of the supply is fully vented to aid with cooling and to the left is a power switch, XFX badge and power connector socket.

XFX Pro Series 450W Power Supply
DC Output	+3.3V	+5V	+12V	-12V	+5Vsb
Max Output	20A	20A	34A	0.5A	2.5A
Max Combined	120W		408W	6W	12.5W

It can deliver 34A to the +12V rail which is quite impressive, especially considering the modest output.

Cables	configuration
24/20 Pin	x1 fixed
CPU 4+4 Pin	x1 fixed
CPU 8 Pin	x1 fixed
PCI-E 6+2pin	x1 fixed
PCI-E 6 pin	x1 fixed
SATA	x6 fixed (two cables)
MOLEX	x6 fixed (two cables)
FDD	x1 fixed

For a model at this specific power output there is more than enough connectivity to sate audience demands. The cables are fully sleeved and high quality.

The box for the XFX Pro 550W power supply is almost identical to the 450W on the previous page. Obviously the output has changed.

Inside there are several power cables, mounting screws and literature on the product.

The same matt finish as the other models in the range, meaning it won't mark or scuff easily, even after rough handling. The big fan and XFX badge takes centerstage in the middle of the chassis.

The front of the supply is vented for maximum air flow and next to this is a power switch, XFX logo and power connector socket.

XFX Pro Series 550W Power Supply
DC Output	+3.3V	+5V	+12V	-12V	+5Vsb
Max Output	24A	24A	44A	0.5A	2.5A
Max Combined	130W		528W	6W	15W

The XFX Pro Series 550W can deliver 44A to the +12V output, compared to 34A with the 450W model we looked at on the last page.

Cables	configuration
24/20 Pin	x1 fixed
CPU 4+4 Pin	x1 fixed
CPU 8 Pin	x1 fixed
PCI-E 6+2pin	x1 fixed
PCI-E 6 pin	x1 fixed
SATA	x9 fixed (3 cables)
MOLEX	x6 fixed (2 cables)
FDD	x1 fixed

Again, there are plenty of cables considering the target audience. The 550W model has 3 more Sata power connectors when compared to the 450W model on the previous page.

The 7 blade 120mm fan is a ADDA AD1212MB-A70GL ball bearing unit which is rated at .33A, 2050 rpm while generating 38dBa of noise and pushing 80.5cfm of air. The 650w, 750w and 850w models in this series use a 9 blade 135mm ADDA ADN512UB-A90 unit.

XFX use high quality Japanese capacitors which are rated to withstand up to 105c. These are conductive Polymer Aluminum Solid Electrolytic Capacitors to help improve operational stability under continued load conditions.

There are also several rows of heatsinks seperating the components which receive air flow from the fan above.  The XFX PSU is supplied with automatic output protection to ensure no damage occurs. This includes Total Power Protection (OPP), Over Voltage Protection (OVP), Over Current Protection (OCP), Short Circuit Protection (SCP) and Over Temperature Protection (OTP).  The cables are sleeved well into the chassis, which helps to ensure no long term damage by fraying. The cabling is well routed and organised with ties.

The fan in the XFX Pro Series 550W unit is different to the 450W model. This is a 120mm AD1212HB-A71GL unit which is a high speed 7 blade ball bearing fan which can push up to 85.2cfm of air. It can rotate up to 2.200rpm and is encased in a glass reinforced Thermoplastic Polyester.

XFX use high quality Japanese capacitors which are rated to withstand up to 105c. These are conductive Polymer Aluminum Solid Electrolytic Capacitors to help improve operational stability under continued load conditions.

There are also several rows of heatsinks seperating the components which receive air flow from the fan above.  The XFX PSU is supplied with automatic output protection to ensure no damage occurs. This includes Total Power Protection (OPP), Over Voltage Protection (OVP), Over Current Protection (OCP), Short Circuit Protection (SCP) and Over Temperature Protection (OTP).  The cables are sleeved well into the chassis, which helps to ensure no long term damage by fraying. The cabling is well routed and organised with ties.

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
• SkyTronic DSL 2 Digital Sound Level Meter (6-130dBa)
• 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
	A	V	A	V	A	V	A	V
75W	1.05	3.35	1.47	5.05	4.84	12.08	0.50	5.05
150W	2.41	3.33	3.17	5.03	9.70	12.07	1.00	5.05
250W	3.69	3.32	5.18	5.02	16.50	12.05	1.50	5.02
350W	4.97	3.31	7.06	5.01	23.52	12.03	2.00	5.00
450W	6.73	3.29	9.15	5.00	31.24	12.01	2.50	4.99

Voltage regulation is solid across all the testing , holding to almost reference levels on the +5V and +3.3V output.

XFX Pro Series 450W	Maximum Load
	479.4

The PSU managed around 480 watts before it would shut down gracefully.

Next we want to try Cross Loading. This basically means loads which are not balanced. If a PC for instance needs 500W on the +12V outputs but something like 30W via the combined 3.3V and +5V outputs then the voltage regulation can fluctuate badly.

Cross Load Testing	+3.3V		+5V		+12V		-12V		+5VSB
	A	V	A	V	A	V	A	V	A	V
385.4W	2.0	3.29	2.0	5.03	30.0	12.07	0.2	-12.06	0.50	5.02
170.5W	18.0	3.27	12.0	4.98	4.0	12.02	0.2	-12.03	0.50	5.00

The XFX PSU handled the Cross loading tests without a problem and we experienced no issues. All the voltages remained within stated tolerances.

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 XFX unit complied with the ATX standard.

AC Ripple (mV p-p)
DC Load	+3.3V	+5V	+12V	5VSB
75W	5	5	10	5
150W	5	5	15	5
250W	5	5	20	10
350W	10	10	30	15
450W	10	10	35	15

Extremely good ripple supression from the XFX unit.

Efficiency (%)
75W	85.21
150W	86.76
250W	87.31
350W	84.97
450W	83.78

Efficiency results are good for a 80 Plus Bronze Certified supply, hitting over 87% at around 50% load. At full load efficiency drops to just under 84% which is still very strong.

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 Power Supply we have taken it into our acoustics room environment and have set our SkyTronic DSL 2 Digital Sound Level Meter (6-130dBa) 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)
75W	28.6
150W	29.4
250W	30.8
350W	33.7
450W	35.9

Generally the unit is quiet, until we get into the final 20% of rated power output, then it can be heard. At full load it is clearly audible, but it is not practical to be running a power supply at the full rated power output for long periods of time.

Temperature (c)
	Intake	Exhaust
75W	35	38
150W	37	40
250W	39	48
350W	42	51
450W	44	55

The 120mm ADDA fan generates a high level of airflow once the temperatures start to rise. At around 80% load the fans do increase and the final resting temperatures at full load are 11c above ambient.

Maximum load	Efficiency
479.4W	80.6

Pushing the PSU above its rated limits generates an efficiency level of around 80.6%. This is not a viable ‘real world’ situation, but its interesting nonetheless.

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
• SkyTronic DSL 2 Digital Sound Level Meter (6-130dBa)
• 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
	A	V	A	V	A	V	A	V
110W	1.18	3.35	1.16	5.06	8.02	12.14	0.50	5.04
220W	2.07	3.32	2.05	5.04	16.11	12.12	0.50	5.04
340W	3.02	3.31	3.05	5.03	25.12	12.10	1.00	5.03
445W	4.12	3.30	4.08	5.01	33.22	12.07	1.50	5.02
550W	5.09	3.28	5.03	5.00	41.01	12.04	2.50	5.01

Another strong series of results across the full range of testing.

XFX Pro Series 550W	Maximum Load
	602.3

Next we want to try Cross Loading. This basically means loads which are not balanced. If a PC for instance needs 500W on the +12V outputs but something like 30W via the combined 3.3V and +5V outputs then the voltage regulation can fluctuate badly.

Cross Load Testing	+3.3V		+5V		+12V		-12V		+5VSB
	A	V	A	V	A	V	A	V	A	V
493W	1.0	3.32	1.0	5.01	40.0	11.98	0.2	-11.97	0.50	5.04
153W	15.0	3.30	15.0	5.00	2.0	12.09	0.2	-12.02	0.50	5.02

Another great set of results from the Cross loading tests. All of the voltages remained within stated tolerances.

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 XFX unit complied with the ATX standard.

AC Ripple (mV p-p)
DC Load	+3.3V	+5V	+12V	5VSB
110W	5	5	10	5
220W	5	5	15	5
340W	5	5	20	10
445W	10	10	25	10
550W	10	10	30	15

Good ripple results across the full range of testing and well within the Ripple Tolerance guidelines.

Efficiency (%)
110W	85.31
220W	86.86
340W	87.42
445W	84.94
550W	83.52

Good results again from the 80 Plus Bronze certified supply, hitting around 87% efficiency at 50% load.

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 Power Supply we have taken it into our acoustics room environment and have set our SkyTronic DSL 2 Digital Sound Level Meter (6-130dBa) 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)
110W	28.4
220W	29.7
340W	31.3
445W	32.8
550W	35.5

Much like the 450W we tested earlier, the supply is quiet until around 75% of the rated load, then the fan kicks in to push more air throughout the chassis.

Temperature (c)
	Intake	Exhaust
110W	35	38
220W	37	40
340W	40	47
445W	42	50
550W	44	54

The 120mm ADDA fan holds temperatures at around 7-8c above ambient. At full load this rises to 10c.

Maximum load	Efficiency
602.3W	80.8

Pushing the PSU above its rated limits generates an efficiency level of around 80.8%. This is not a viable ‘real world’ situation, but its interesting nonetheless.

XFX have rounded out their Pro Series with two very capable units at the lower end of the price spectrum. Both 450W and 550W supplies are well designed with fantastic build quality. We don't always comment on the packaging of a product, but XFX really excel at attracting the eye within a store environment.

Technically, both supplies have stable regulation and cope well with varying loads, as our crossloading results verify. Ripple results are equally impressive and efficiency levels are also very good, exceeding the 80 Plus Bronze certification they have achieved. Noise emissions are reasonably good with the large ADDA fans keeping the temperatures well within check, even under high continual loads.

As we said last time, this series from XFX is not released to break any performance records, but they are a well priced range of supplies with good internal design and high reliability. UK pricing has not yet been confirmed with us, however as the 650W unit was retailing for £65 you should expect to see the 550W for around £55 and the 450W for £45 or less.

KitGuru says: Quality products at great prices, the Pro Series has been a great success for XFX.

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