Seasonic PRIME TX-650 Titanium PSU (2020) Review

1. Introduction2. Bundle & Cabling3. External4. Internal5. Methodology and Testing6. Closing Thoughts7. View All Pages

Today we have a new power supply to grace our test labs – the new, revised Seasonic Prime TX650 Titanium rated power supply. This new TX650 is part of an internal company rebrand as they consolidate their range.This ‘OneSeasonic’ revamp is a calculated move to repackage and rename their supplies with an easier to follow overview and tier separation. 

The supply we review today measures 150 x 86 x 170 mm (W x H x D) and is equipped with a 135mm Fluid Dynamic Bearing Fan (FDB) which can operate in semi passive mode. This is a flagship Seasonic supply, priced at around £185 in the United Kingdom. Titanium rated power supplies are expensive, but guarantee maximum efficiency ratings.

The single rail is rated to 54A and Seasonic cover this unit with a substantial 12 year warranty. Seasonic are also claiming very tight micro tolerance load regulation between 0.5% and 1.0%.

Here is how Seasonic are breaking down the model numbers, in case you wondered. ‘PRIME' is obviously the Series identifier (‘FOCUS' and ‘CORE' are the other series). The ‘T' stands for ‘Titanium' (‘P' is Platinum, ‘G' is Gold and B' is Bronze) and the ‘X' means it is fully modular. (‘M' is Semi Modular, and ‘C' is fixed cable design). The final number ‘650' In this case, is obviously the wattage. There are also 750 watt, 850 watt and 1000 watt models in this range, as well as Fanless 600 watt and 700 watt models (called the TX-600 and TX-700).

Here is a list of the ‘OneSeasonic' changes made to the unit:

• removed some inline capacitors.
• added a power supply tester to each box.
• updated some cable quantities to reflect user requirement.
• improved ripple and noise performance with a double-layer PCB.
• updated the appearance of the PSU housing.
• changed warranty sticker to a round shaped one.
• created new rating labels.
• improved PSU- and cable bags.
• updated printed documentation.

Seasonic's Prime range of power supplies ship in a shiny silver box – to indicate the Titanium efficiency rating. Is it super reflective and a nightmare to photograph! On the front of the box there are some key specifications listed, along with the 12 year warranty rating.

Pretty nice to see the European Hardware Association (EHA) logo on the top of the box. KitGuru is a part of the EHA.

The rear of the box highlights the 80 Plus Titanium rated efficiency and the Premium Hybrid Fan Control.

Seasonic include a regional specific power plug, literature on the power supply, cable ties and a bag of modular cables.

Seasonic also supply a PSU tester, which is very handy to have in the arsenal. This is a new cable bag design, which is slightly improved over the older one. Seasonic have also included a new installation guide pamphlet which may be useful for the less experienced audience who are wondering what on earth to do next.

The modular cables are all flat ribbon style for ease of routing, apart from the main ATX cable which is sleeved. The new 650W model ships with two CPU power connector cables.

The Seasonic Prime TX650 Titanium power supply is nicely finished to the standards we expect from Seasonic.

The image above is taken from part of a document that Seasonic sent me – with a ‘before' and ‘after' analysis of the old v new Prime TX appearance.

The FDB fan is hidden behind the top honeycomb chassis. We will take a look at this shortly when we open the unit later in the article.

One side of the power supply is vented to help with air flow. There is a power connector, switch and hybrid button here. If the hybrid mode is enabled, the fan will not spin at lower loads. If this switch is disabled then the fan will always spin.

The other side of the power supply is home to the modular bay – with all the cable connector ports clearly labelled for ease of use.

Seasonic Prime TX650 (SSR-650TR)
DC Output	+3.3V	+5V	+12V	-12V	+5Vsb
Max Output	20A	20A	54A	0.3A	3.0A
Total Power	100W		648W	3.6W	15W
	650W

The Seasonic Prime TX650 Titanium power supply delivers 54A on the +12V for 648 watts of the total output.

Seasonic are using a Hong Hua FSB fan model number ‘HA13525L12F-Z'. Rated 0.22A 12V and 1,600 rpm. Seasonic have been using Hong Hua fans in many of their units in the last year. These Fluid Dynamic bearing fans offer long life and quiet operation.

Below - a High Resolution Gallery of the internal layout of the Power supply.

Soldering quality throughout is excellent as we would expect from a high quality brand such as Seasonic. They have removed some of their inline capacitors and have adopted a new double layer PCB design to improve ripple and noise performance.  The back panel is connected to the PCB by a copper plate rather than cables.

Due to the high efficiency of this power supply Seasonic don't have to populate the PCB with too many heatsinks.

Seasonic are using 105c high grade Japanese capacitors throughout the primary and secondary stages. The primary hold up caps are 470uF 400V rated, 105c. for a total of 940uF.

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. We run at 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 in a single +12V configuration.

DC Output Load Regulation
Combined DC Load	+3.3V		+5V		+12V		+5VSB		-12V
	A	V	A	V	A	V	A	V	A	V
65W	0.92	3.34	0.88	5.01	4.42	12.03	0.50	5.02	0.20	-12.03
130W	1.63	3.34	1.65	5.01	9.18	12.03	0.50	5.02	0.20	-12.02
325W	2.93	3.34	3.00	5.01	24.25	12.03	1.50	5.02	0.20	-12.02
490W	4.04	3.33	4.10	5.01	36.90	12.02	2.00	5.02	0.30	-12.02
650W	5.00	3.33	5.30	5.00	49.67	12.02	2.50	5.02	0.30	-12.01

Load regulation is fantastic on the +12V rail, as well as the minor rails.

Seasonic PRIME TX-650 Platinum	Maximum Load
	798 watts

We managed to get the PSU to deliver 798 watts before it would shut down, delivering almost 150 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	3.33	1.0	5.02	48.0	12.02	0.2	-12.02	0.50	5.01
145W	12.0	3.31	15.0	4.99	2.0	12.03	0.2	-12.02	0.50	5.02

The unit passed our cross load test, and held rock solid throughout.

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	5	10	5

Ripple suppression is extremely impressive. hitting a maximum of 10mV at 100% load via the +12V rail. It passed all these tests with flying colours.

Efficiency (%)
152W	94.2
270W	95.8
400W	96.0
523W	95.2
650W	94.8

Efficiency peaked at just over 96% which is seriously impressive. At full load this efficiency drops to almost 95%. Stunning results all round.

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	31.3
523W	34.3
650W	36.1

Noise levels are low until higher loads are placed on the unit when the fan has to spin up to compensate for rising temperatures inside the chassis.

Temperature (c)
	Intake	Exhaust
152W	36	38
270W	39	43
400W	42	46
523W	44	48
650W	47	56

At full load we measured temperatures around 56c.

Maximum load	Efficiency
798 watts	93.7

At 798 watts, the efficiency level measures 93.7%. Not a practical situation to be running 24/7, but worth noting.

The is no doubt that at £185, the Seasonic PRIME TX650 Titanium (SST-650TR) power supply is a considerable investment. If you have read the full review today however you will see that this is one of the finest power supplies available on the market in 2020.

The Titanium range of power supplies has always been Seasonic's showcase of engineering capabilities. It is a HALO product which reinforces that Seasonic are the market leader.

These new revised units under the internal ‘OneSeasonic’ branding maintain the high standards we expect from Seasonic, but in reality this buzzword means little to the end consumer. Seasonic have removed some of the inline capacitors from the cables, changed some cable quantities under end user feedback and have implemented a new double layer PCB.

The other changes are more cosmetic by nature – no one really will notice that the new warranty sticker for instance is round and not square or that they have created new rating labels for the chassis. On a slightly more relevant note for our audience, Seasonic have improved the cable bags and have included printed documentation which should aid inexperienced users during the system build.

On a technical level, this power supply is one of the best we have ever tested. Efficiency peaked at just over 96% and the DC output and load regulation is class leading falling under 1%. It also passed the cross load test without any problems.

Ripple suppression is stellar too, with both +3.3V and +5V rails peaking at only 5mV. The +12 Rail peaked at 10mV – some of the best results we have seen from any unit tested in our labs.

This is a fully modular power supply, there are no hardwired cables getting in the way during a system build and the addition of an extra CPU connector with the new design should help satisfy the demanding audience with the funds available for a purchase.

When we last reviewed the previous Seasonic Prime 650W Titanium unit back in August 2016, Seasonic were offering a 10 year warranty. This has now been extended to 12 years for added peace of mind. They are clearly proud to stand behind their long term reliability.

You can buy the Seasonic PRIME TX650 Titanium Power supply from Overclockers UK for £184.99 HERE.

Pros:

• Exceptionally high build quality.
• technically one of the best units we have tested.
• Fully modular.
• Good bundle.
• 12 year warranty.
• 96%+ efficiency.
• delivered around 800 watts before shutting down.
• 105c high grade Japanese capacitors throughout.

Cons:

• Titanium rated – they are expensive.

KitGuru says: Another class leading power supply from the market leader Seasonic. If you want the best possible power, backed up by a 12 year warranty this TX-650 unit deserves serious consideration.

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