Seasonic Prime 650W Titanium Power Supply Review

1. Introduction2. Seasonic Prime 650W Titanium (Bundle & Cables)3. Seasonic Prime 650W Titanium (External)4. Seasonic Prime 650W Titanium (Internal)5. Super High Res Gallery6. Testing Methodology & Results7. Closing Thoughts8. View All Pages

Today we take a look at the new Seasonic Prime 650W Titanium power supply, the third in a series of reviews we have published to cover the current range of PRIME units available. This is a fully modular 80 Plus Titanium certified power supply which features a high grade 135mm Fluid Dynamic Bearing fan.

Seasonic have released 650W, 750W and 850W PRIME supplies in recent months and they have a 1000W unit coming in November. This more powerful unit is clearly designed for the small audience using multiple high end graphics cards in Crossfire or SLi.

At the end of the year the plans are for Seasonic to release an additional 600W fanless unit – specifically targeting the enthusiast audience who love the ‘sound of silence’. Based on the Seasonic track record in our labs we have high hopes for this upcoming fan less 600 watt power supply.

Seasonic also have plans to release Platinum and Gold PRIME supplies later this year at the end of Q3 and in Q4.

PRIME Overview:

• Ultra-High Efficiency, 80 PLUS® Titanium Certified.
• Micro Tolerance Load Regulation.
• Top-Quality 135 mm Fluid Dynamic Bearing Fan.
• Premium Hybrid Fan Control.
• Super lower Ripple Noise (under 20 mV).
• Extended Hold-up Time (Above 30 ms).
• Fully Modular Cabling Design.
• Multi-GPU Technologies Supported.
• Gold-Plated High Current Terminals.

Seasonic are using super high gloss, reflective, box designs for their PRIME series. A nightmare to photograph, and much better looking in the flesh.

Some details of the unit are exposed on the back of the box.

The bundle includes a lot of little extras to enhance the experience. All the modular cables are stored in a cardboard box. Seasonic include a user manual, a case badge, sticker, mounting screws and plastic and branded felt cable ties.

The power supply is protected inside a felt bag. There is also a regional specific power cable included.

Seasonic have sleeved the main motherboard cable. All the other cables are ribbon style, flat – ideal for saving space and improving airflow when routing cables. They also include a regional specific power cable.

The cables are all very high grade, which is reassuring to see.

Both Prime 650 and 750 watt units are equipped with 4 PCI-E 6+2 power connectors – catering for the SLI and Crossfire audience. The 750 watt unit has 4 more SATA connectors, increasing from 6 on the 650W to 10 on the 750W. The 850W unit has 6x PCI-E 6+2 power connectors.

Above, a diagram of the cable breakdown and lengths.

The Seasonic Prime power supplies are fantastic looking power supplies. Regular readers of KitGuru will see the finish is exactly the same throughout the range. You weren't expecting one of them to be pink, right?

The colour scheme is actually really important today, because more and more enthusiast users are colour coordinating their system so they match. Black and chrome/silver works with any scheme.

The quality of the paintwork is no different either. Its top notch. I like the overall appearance of the vents on the sides too. The fan is not that visible behind the chrome surround, but we will take a closer look inside, soon.

One side of the Prime Titanium power supply is home to the modular cabling connectors. The main M/B connectors are indicated along the bottom of the panel – clearly labelled. The Peripheral/SATA/Molex connectors are visible in a bank of two and three along the top right side. On the other side are all the CPU and PCI-e connectors in a row of 2 and 2 from top to bottom (4 in total). The 850W model has 8 in total.

The other side of the PRIME is vented to help ensure there is plenty of airflow movement over the components.

There is also a switch for Hybrid mode – allowing the fan to be disabled completely when the unit drops to a specific temperature threshold. Seasonic claim the Hybrid Fanless mode works up to:

• Approximately 50 % (±5 %) of system load at 25 °C.
• Approximately 30 % (±5 %) of system load at 40 °C.

Above we can see the specifications of the power supply.

Seasonic Prime 650W Titanium Power Supply
DC Output	+3.3V	+5V	+12V	-12V	+5Vsb
Max Output	20A	20A	54A	0.3A	3A
Total Power	100W		648W	3.6W	15W
	650W

This 650W Prime can deliver 54A to the +12V rail. This is plenty of power to support an SLI or Crossfire configuration.

Seasonic are using a Hong Hua 135mm fan, Model number HA13525M12F-Z. This is the exact same fan fitted in the 750W and 850W PRIME units.

This is a Fluid Dynamic Bearing Fan selected for low noise characteristics. Regular readers may recall that the Seasonic Snow Silent 750W unit shipped with a smaller 120mm fan from the same company so its interesting, and likely a good move that Seasonic are adopting larger fans. Larger fans of similar quality are able to push more air at the same speeds, likely often spinning slower to reduce noise emissions.

The soldering quality throughout is top drawer and it is clear that Seasonic have succeeded in reducing system clutter thanks to their new internal cable free connection design. There is a copper plate connecting the back panel to the main PCB to increase reliability and improve performance. They are increasing their use of paste solder throughout the design for quality reasons.

Seasonic are offering a full 10 year warranty with these power supplies so it is clear they are confident of long term reliability and stability.

The Prime supply adopts high grade Japanese capacitors throughout both primary and secondary stages. The primary stage is served by two 105c Nippon Chemi Con capacitors rated at 400v 450uF each (for a combined total of 900uF).

The 750W Prime is served by two 105c Nippon Chemi Con capacitors rated at 400v 560uF and 400v 450uF (for a combined total of 1010uF). The 850W Prime is served by two 105c Nippon Chemi Con capacitors rated at 400v 650uF and 400v 450uF (for a combined total of 1100uF).

On this page we present a Super High resolution gallery of the Seasonic Prime 850W power supply. These pictures were taken with a Leica S Medium Format camera with a 70mm Leica Summarit S 70mm F2.5 ASPH CS lens. These pictures are 36MP so may take a while to open depending on your connection. Right click and save as to get them to your desktop.

If you use these pictures on another website or publication please credit Kitguru.net in some way as the source, linking to this review specifically.

 

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		-12V
	A	V	A	V	A	V	A	V	A	V
152W	2.05	3.34	2.04	5.02	10.12	12.04	0.50	5.01	0.20	-12.02
270W	3.03	3.34	3.05	5.02	19.14	12.03	0.50	5.01	0.30	-12.02
400W	4.05	3.33	5.02	5.02	29.18	12.03	1.00	5.01	0.30	-12.02
523W	6.09	3.33	7.04	5.01	38.18	12.02	1.50	5.00	0.30	-12.01
650W	8.00	3.33	9.00	5.01	48.00	12.02	2.50	5.00	0.30	-12.01

Load regulation is as impressive as the other units we have tested in the PRIME range.

Seasonic Prime 650W Titanium	Maximum Load
	844W

We managed to get the PSU to deliver 844 watts before it would shut down, delivering almost 200 watts more than the rated specifications!

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
590W	1.0	3.34	1.0	5.02	48.0	12.02	0.2	-12.03	0.50	5.00
145W	12.0	3.32	15.0	5.01	2.0	12.05	0.2	-12.02	0.50	5.01

The unit passed our cross load test without any problems. It was hit with 48A on the +12V rail and it held at 12.02.

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 unit complied with the ATX standard.

AC Ripple (mV p-p)
DC Load	+3.3V	+5V	+12V	5VSB
152W	5	5	5	5
270W	5	5	5	5
400W	5	5	10	5
523W	5	5	10	5
650W	5	10	15	5

Ripple suppression is stellar, holding a position within the top couple of percent of units we have tested in the last year.

Efficiency (%)
152W	92.67
270W	94.33
400W	95.78
523W	94.64
650W	93.48

Efficiency is superb, peaking at around 96% and dropping to 93.5% at full 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 Refrigerator
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)
152W	<28.0
270W	<28.0
400W	31.8
523W	33.7
650W	34.3

Noise levels are low throughout the load range. At full load the fan spins up a little, hitting just over 34dBa. This is still relatively quiet and masked by several case fans.

Temperature (c)
	Intake	Exhaust
152W	36	38
270W	39	41
400W	42	44
523W	44	49
650W	47	54

The very high efficiency levels of the power supply ensure that the fan never has to work that hard – its a cool running unit as well.

Maximum load	Efficiency
844 watts	92.6

At 844 watts, the efficiency level measures 92.6%. Not a practical situation to be running 24/7, but worth noting.

This is the third Titanium grade PRIME power supply that we have analysed in recent months, and it is business as usual for Seasonic. Yet again the quality of the power delivery is first class, satisfying the most demanding of enthusiast user.

The Titanium Prime power supplies really are a Seasonic showcase of engineering capabilities. The company are standing by these units by offering a market leading 10 year warranty. They are clearly confident that these Titanium PRIME not only deliver the goods, but will still be kicking when you are likely on your second or third system change.

The appearance of a power supply will likely split opinion but we can't see anyone really disliking the appearance of the PRIME power supplies. Seasonic have opted for neutral black and silver colours which will pair up well with any colour scheme of LED system lighting.

Seasonic have spared no expense in the design of the Titanium Prime. They have created a cable free connection design with a copper plate connecting the main PCB to the back panel for increased reliability and enhanced performance. They have adopted high grade Nippon Chemi Con 105c rated capacitors in the primary stage, with 105c rated capacitors also incorporated into the secondary stage.

As with the other units we have tested recently, there is little we can fault. These units excel with ripple suppression and load regulation. They are in the top 2% of units we have tested in the last 3 years. We were able to hold a load of 820 watts for some time without an issue. Seasonic are well known to over specify their power supplies and this hasn't changed this year. With a 10 year warranty in place, taking all measures possible to reduce RMA's makes perfect sense.

The pure modular design and low noise levels will make sense for a lot of people who have a system running in their living room or bedroom. It is unlikely you will hear this unit over even two high grade system chassis fans.

The only downside is that these supplies are expensive, but they are flagship units designed to deliver the finest quality power possible. If they are too rich for your blood then Seasonic also have plans to release less expensive Platinum and Gold PRIME supplies later this year at the end of Q3 and in Q4. Read the reviews first on KitGuru.

Discuss on our Facebook page, over HERE.

The Seasonic Prime 650W Titanium power supply is available from Overclockers UK for £169.95 inc vat HERE.

Pros:

• exceptionally high build quality.
• large fan is quiet.
• technically as good as we have seen.
• 10 year warranty.
• high efficiency levels.
• almost delivered 850 watts!

Cons:

• Expensive.

Kitguru says: The Seasonic Prime 650W Titanium power supply is another incredibly high grade unit that will suit the audience who want to ensure they are feeding the best possible power to all their expensive components.

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