Seasonic Prime 750W Titanium Power Supply Review

1. Introduction2. Seasonic Prime 750W Titanium (Bundle & Cables)3. Seasonic Prime 750W Titanium (External)4. Seasonic Prime 750W Titanium (Internal)5. Super High Res Gallery6. Testing Methodology and Results7. Closing Thoughts8. View All Pages

It has been talked about and teased for many months, but today we finally get to present our analysis of the new PRIME 750 watt power supply, a pivotal supply in a very important new range for market leading manufacturer Seasonic.

Seasonic are releasing Titanium rated 650W and 750W supplies now, with a more powerful 850W unit due for release in August … followed by the flagship 1000W unit with availability set for November. 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.

While we are focusing on the new Titanium 750 watt unit today, Seasonic also have plans to release Platinum and Gold PRIME supplies later this year at the end of Q3 and in Q4. Over the coming months we hope to get our hands on a wide selection of units to supplement this PRIME launch review today.

The Seasonic PRIME Titanium range is fully modular, and they incorporate low noise 135mm Fluid Dynamic Bearing fan.

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.

The Seasonic Prime 750W arrives in a lovely shiny, silver box that certainly attracts the eye.

The bundle is quite extensive, especially for a power supply. There are two kinds of cable ties, mounting screws, a user manual, installation guide and two shiny stickers. All are enclosed within a resealable flat plastic wallet.

The power supply is encased in thick Styrofoam. At the side of the main power supply is a cardboard box, which is home to all the modular cabling.

The power supply is protected inside a soft black, felt bag, shown above.

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.

Above, a diagram of the cable breakdown and lengths.

The Seasonic PRIME 750W is beautifully finished and one of the highest grade units we have seen this year.

All the paintwork is evenly applied and we like their new design for the vents on the top. Its certainly eye catching, but we appreciate they haven't went overboard with a plethora of colours – its a rather simple gloss silver and black scheme. The paintwork passed our scratch test with flying colours. This test involves running the head of a Philips head screwdriver down the side panel with light to moderate force – many lower quality painted panels will leave a noticeable mark or strip completely.

Some of you will have noted it is difficult to even see the fan behind the vents and we would imagine this is intentional to keep the clutter to a minimum. We will take a look at the specific model of fan later in the review when we open the chassis.

The attention to detail is high – the side panels are sculpted to regress inwards, towards the Seasonic name on one edge of the side panels. The PRIME Titanium logo takes pride of place on the other edge. Build quality is at the highest level.

One side of the Prime Titanium is home to all 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 1, 3 and 2 from top to bottom (6 in total).

The other side of the PRIME is fully vented to aid with airflow. There is a power switch and connector at the side. 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 750W Titanium Power Supply
DC Output	+3.3V	+5V	+12V	-12V	+5Vsb
Max Output	20A	20A	62A	0.3A	3A
Total Power	100W		744W	3.6W	15W
	750W

This power supply can deliver 62A on the +12V rail which is the same as the Seasonic Snow Silent 750W which we reviewed way back in May 2015 (review HERE). Plenty of power on hand for a powerful SLI and Crossfire configuration.

Seasonic are using a Hong Hua 135mm fan, Model number HA13525M12F-Z. 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.

Seasonic told us that many of their customers have asked for a longer hold up time. Intel specifications state 16ms, and Seasonic worked hard to bring the PRIME units out at a rating of 30ms.

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 560uF and 400v 450uF (for a combined total of 1010uF).

On this page we present a Super High resolution gallery of the Seasonic Prime 750W 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.

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

We test with the +12V in single rail mode.

DC Output Load Regulation
Combined DC Load	+3.3V		+5V		+12V		+5VSB		-12V
	A	V	A	V	A	V	A	V	A	V
75W	1.23	3.34	1.19	5.02	4.95	12.04	0.50	5.02	0.20	-12.03
150W	2.17	3.34	2.83	5.02	10.07	12.04	1.00	5.02	0.30	-12.03
375W	6.15	3.33	6.05	5.01	26.15	12.03	1.50	5.01	0.50	-12.02
565W	10.31	3.33	10.86	5.01	38.34	12.02	2.00	5.01	0.60	-12.02
750W	10.72	3.33	13.84	5.00	53.59	12.01	3.00	5.00	0.80	-12.02

Load regulation is fantastic, holding tight and well within 1%.

Seasonic Prime 750W Titanium	Maximum Load
	902W

We managed to reach around 902W before the unit would shut down gracefully, after the protection kicked in. This is a full 150watts more than the unit is officially rated. An exceptional result.

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
734W	1.0	3.34	1.0	5.01	60.0	12.03	0.2	-12.02	0.50	5.01
154W	15.0	3.33	15.0	5.01	2.0	12.04	0.2	-12.02	0.50	5.01

The unit passes our Cross Load testing with flying colours. When hit with 60 Amps the unit holds steady at 12.03 Volts.

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
75W	5	5	5	5
150W	5	5	10	5
375W	5	5	10	5
565W	5	10	15	5
750W	5	10	15	5

These really are exceptional results. The +3.3V and +5V output peak at 5mV and 10mV respectively under full load. The +12V rail peaks at 15mV under full load conditions.

Efficiency (%)
75W	91.98
150W	92.88
375W	95.78
565W	93.75
750W	93.22

Power efficiency rates as excellent, hitting a peak over 95.7% at 50% load. At full load it drops to 93.2%, another stellar result.

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 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 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)
75W	<28.0
150W	<28.0
375W	29.7
565W	32.4
750W	33.2

The large fan in the Prime 750W spins relatively slowly, even under heavy load situations. It is only audible really when the load exceeds 650 watts, but it is never that intrusive due to the relatively low pitch of the fan.

Temperature (c)
	Intake	Exhaust
75W	36	38
150W	38	40
375W	39	43
565W	45	50
750W	47	57

The high levels of efficiency of this unit help reduce expelled heat. At full load we measured a +10c variable.

Maximum load	Efficiency
902W	92.3

For those interested, we measured efficiency when stressing the unit to breaking point. 92.3 percent efficiency at 902W … hardly practical, but interesting regardless.

There is no doubt in my mind that the Seasonic Prime 750W Titanium has entered the market right at the top of the food chain. It has been a long time in development, but the release of Prime Titanium galvanises Seasonic's position as a leader in this sector.

We don't often comment on the appearance of a power supply, but the Prime certainly ticks the right boxes. We think it is an elegant unit from all angles and the paintwork is both deep and resilient to scratches. The little ‘air intake' style indentations on the side panels certainly enhance the appearance.

Additionally, the lack of coloured stickers and the adoption of an subdued two tone colour scheme will ensure the unit will look great behind a windowed panel, regardless of any LED lighting used.

We have to give Seasonic kudos for their internal design implementation. 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.

Technically we can find nothing to fault. The Titanium rated unit excels in key areas, including ripple suppression, load regulation and it passed our cross load test without a hitch. We were able to hold load at 900 watts without the unit switching off which is a good indication of how over specified the core design is. I am glad to see Seasonic haven't suddenly changed their long term strategy this year.

The pure modular design and low noise levels will suit the demanding enthusiast audience building inside a space restricted chassis. The Hybrid Fanless mode ensures the Prime would even make an ideal backbone for a powerful media/gaming center, positioned close to a HDTV set in the living room.

Seasonic are standing by these units and are offering a full 10 year warranty, which is reassuring but not surprising considering the quality of the internal build.

The only downside? A quality 750 watt Titanium rated power supply like this doesn't come cheap, so be prepared to hit the bank balance, hard.

You can buy the Seasonic Prime Titanium 750 watt power supply from Overclockers UK for £189.95 inc vat HERE.

Discuss on our Facebook page, over HERE.

Pros:

• very high build quality.
• large fan is quiet.
• technically class leading.
• 10 year warranty.
• high levels of efficiency.

Cons:

• not cheap.

Kitguru says: The Seasonic Prime 750W is a class leading power supply backed up with a 10 year warranty. It is a quiet and technically stellar unit which reinforces Seasonic's reputation as the market leader. The PRIME Titanium 750W is already setting itself up as a key contender for power supply of the year 2016.

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