A review of a pair of SeaSonic Focus Plus Gold 750W and 850W power supplies. Over-Gold, but under-Platinum #2

As a rule, the average modern computer which can cope with games and tasks more complicated than CS:GO paired with the biggest breeding ground of inadequates in the world, where the probability of meeting his sudden father in his words tends to infinity, has a power supply for about 550-700 watts. This is more than enough for any system with almost any video card, except for the “two-headed”. More powerful units are purchased either on the principle of “more power than the neighbor’s” or out of ignorance, or in order to sleep better. Earlier I reviewed two SeaSonic Focus Plus Gold 550W and 650W power supplies, but today we will have a look at their two bigger brothers, the 750W and 850W models.

Author: No1seBR

In the same context, we can not avoid touching on an interesting topic concerning the power supply and whether it is worth overpaying for a “wattier” model. To understand this urban legend, consider the following example. Let’s assume the real consumption of the system is 500 W. A good 650 watt PSU will last you for more than a long time. But what if you buy an 850W or even a 1000W unit? The curve of the efficiency as a function of the load is not important, because in both cases the efficiency will be at the high end of the range, but the fan is contributing its share. A good 850W PSU with a 500W load will make less noise than a 650W PSU with the same 500W load. Here, of course, everything depends on the specific manufacturer and the specific model, but for the most part, it’s a fact.

That is why in the pursuit of silence, even if this race is endless, in some cases it is more reasonable to take a more powerful unit with a lower certificate than a less powerful one with a better certificate. To be more specific: a SeaSonic Focus Plus Gold 850 costs $110, and for every penny of that cost a SeaSonic Focus Plus Platinum 650W. In this bout the Gold one will be quieter info 100% and a little spoiler at the same time .

Today we are reviewing two SeaSonic Focus Plus Gold 750W SSR-750FX and 850W SSR-850FX power supplies – a continuation albeit original of the first part where we reviewed the 550W and 650W versions.

Packing, kitting, cables

Let’s start traditionally with the box. The units are packaged in a box with a combination of black and shimmering gold, which as for “Gold” units fits just right. Also the packaging is not to be faulted in the amount of technical information. Literally everything is there: the datasheet, a list of cables, a mention of the 10 year warranty and the main “chips”.

Inside, all modular cables and the incoming signal cable are placed in a separate bag. The unit itself is also in a pouch, but simpler. Be careful with the pouch for the modular cables. There are a lot of cables, the bag is small and it is not made of Kevlar fibers. While trying to shove all the cables back in, one of the pouches tore=

Among other things in the kit there is a user manual including in American with a normal translation , about a dozen plastic zip ties, three branded Velcro ties and a sticker with the series logo.

Although the number of modular cable connectors for the 750 and 850W versions is the same, and exactly the same as for the 550 and 650W versions, the number of cables themselves are different.

The 750W version comes with:

• 1x ATX 20+4 pin
• 2x EPS/ATX12V 4+4 pin
• 4x PCI-Ex Power 6+2 pin
• 8x SATA
• 3x Molex
• 1x Floppy.

The 850 watt version comes with it:

• 1x ATX 20+4 pin
• 2x EPS/ATX12V 4+4 pin
• 6x PCI-Ex Power 6+2 pin
• 10x SATA
• 5x Molex
• 1x Floppy.

The cable lengths and connector spacing in the following picture:

Some of the cables are braided namely the main 24-pin connector, the CPU power connector and the auxiliary PCI-E Power connector , and the others are just flat. Also the loaded lines, i.e. those in the braid, have gold-plated contacts. Gold-plated ATX 20+4 pin and EPS/ATX12V 4+4 pin are not really necessary, but for powering video cards – the masthead, as I tirelessly repeat in every review.

As for the number of cables and connectors, it’s OK. Set is quite in line with the power. Except that I would like to see 6, not 4, PCI-E Power slots for the 750W model. On power unit will bear, and on the case of the unit too there is an additional socket.

Appearance and Features

The first thing I want to say: SeaSonic Focus Plus Gold power supplies are tight. Considering dimensions of 86 x 149 x 139 mm it is the smallest size allowed by ATX standard the reviewed models weigh quite good, and it is strange. And going one chapter ahead, I want to say, that it’s hard to answer where the weight came from. There aren’t many radiators inside, and the ones available aren’t the biggest. Units with 80 Plus Gold energy efficiency certifications have been enough in my hands. These are some of the heaviest.

You know, nothing really changes. Just like 15 years ago we measured the quality of a power supply by its heaviness and now the same song. This criterion is important, because it demonstrates at least savings on the thickness of the case metal, and the case is the first thing they save on. It’s noble 1-millimeter steel. You can step on it with one foot and shift the whole body weight to this foot and it will hold 80 kg will hold, I checked . I will also note the good quality of the painting. So-called “near-Chinese” power supplies scratch literally on dust.

To give you more rigidity SeaSonic engineers made another cool thing that I have not seen before in the units: special “latches” to connect the top and bottom. They don’t let the panel with the connectors and the opposite one, where the sieve is, “walk around”. Again, easier to assemble well, this is such a thing . And I completely agree that the previous three paragraphs in no way affect the technical performance and reliability, but it shows immediately the general attitude of the manufacturer to the product. And the first impression, as you know, is often the right one.

Concerning appearance, the SeaSonic Focus Plus Gold are quite good looking ones with plenty of names of the manufacturing company and the series. It’s literally on every facet. The side edges are additionally decorated with geometric embossing.

The 750W and 850W models have the same set of connectors on the connector panel despite the difference in power. The 850W will use all the connectors, but the 750W will not have any extra connectors. However, all of them work. You can connect the cables to anything, and if you can find such cables somewhere else you can make them yourself , the connectivity will expand.

On the rear panel there is a button to turn the unit on/off a jack for the incoming signal a mention that the unit operates in the 100-240V range and does not care about voltage sags/slips and a button to activate the hybrid fan mode. When the “Hybrid Mode” button is pushed the fan rotates only at 30% of load, according to SeaSonic. In fact depending on the temperature the propeller starts spinning only from 40-50%.

Another funny thing: on the flip side “Hybrid Mode” label clearly looks like 300W.

And finally, the traditional sticker pictures on the blocks with technical specifications. On a 12V line the units are able to deliver almost 100% of their power 744 and 840W 62 and 70A . For lightly loaded 3.3V and 5V lines, a total of up to 100 watts is allowed. Nothing outstanding here. Typical figures of a modern high quality unit.

Internal device

The details of the inner workings of the SeaSonic Focus Plus Gold units were covered in the review of the 550 and 650W versions. There are no significant differences due to the fact that these units are from the same manufacturer and from the same series. Therefore it makes no sense to pour over nothing into nothing over a second circle, and further we will talk only about the most basic points and differences.

All models in the Focus Plus Gold series are very similar to each other. To understand, even the 550 watt and 850 watt versions, where there seems to be a 300 watt difference, are identical in almost everything. All transformers and capacitors except for the most basic one even have the same markings and capacities. The topology, quantity and quality of used components are absolutely identical. The only difference is the capacity of the input capacitor, the transistors and Schottky diode used and of course the “firmware” of the box. At least this is what you can see and we can see almost everything .

As for the input capacitor, the 750W model uses a 105-degree “bank” with a capacity of 560 uF, while the 850W model has 650 uF. In terms of capacity it’s just fine. Neither good nor bad.

SeaSonic did not skimp on the bundling. High-quality 105-degree electrolytic capacitors all by Nippon Chemicon are used not only in the 12 V line load, but on the secondary lines too. There are also solid state “capacitors” on the secondary lines.

The fan is a 120 mm “Carlson” Hong Hua HA1225H12F-Z on hydrodynamic bearing and rotational speed up to 2200 rpm. Hydrodynamic bearings were once the most expensive and are now the most common. Generally speaking, SeaSonic claims 50k. Hours of MTBF, but in actuality, this type of bearing lasts approximately twice as long. And 50,000 hours is 5.7 years of continuous operation.

Testing at

To test power supplies, we use a partially homemade stand based on field-effect transistors. The working principle is simple: current is converted into heat dissipated by a massive heat sink and multiple fans. In essence it is a heater that runs on 12 volts. The load bench lets you vary the power from 100W to 1500W in increments of 10 watts.

To determine the efficiency, which is one of the key characteristics of a power supply, compare the input power and output power with a simple household wattmeter. By simple calculations we find the efficiency factor. This method of measurement, of course, has a certain error, but it does not exceed 1%.

As a rule the power supply is one of the noisiest parts in the PC. Unfortunately it is not possible to measure the noise level in decibels. The roar of the load stand fans multiplies all these attempts by zero, both near and farther away. Therefore, the graphs show the fan speed readings. 120-140 mm fan becomes audible from about 1000 rpm, 1500 rpm – clearly audible under open bench conditions .

Photos show temperatures at 100% load after a 15 minute warmup. Keep in mind that the measurements were taken with the top part ajar and in the open test bench, so in real life the temperatures would be different.

Testing of the protections showed that the protection on the secondary lines of both units tripped at 28A load. On the 12V line, the 750W model has the protection triggered at 960 watts, which is 80 amps, and that overloaded by 28%. In turn, the 850 watt model at about 1060 watts of load which is 88 amps and 25% overload . As you can see, as the power increases, the overload level decreases. Recall that the 550W model tolerated 30% overload.

This time we are going to add something special. I have a room where the air temperature can be raised to 50+ degrees and where there is a lot of “iron”, decent consuming. Of course, at 22-24 degrees in the living room the unit will be comfortable, which can also be seen in the temperature readings above, but let’s put the unit in extreme conditions. Here you can not exactly regulate the load, but I have tried to get closer to 750 W from the socket by adjusting frequencies. The 750 watt unit was the one being tested. For more PCI-Ex Power slots we took another cable from 850W Power kit. And that’s the way it’s been left for 24 hours. It’s not my power supply, in case SeaSonic will forgive me something =

Everything held up. And it was about 50 in the room as a whole, but in the place where the unit was, it must have been 60+. The unit fan was spinning down to about 2150 rpm. The noise, of course, was already. As for the temperature readings in this mode of operation, they were as follows:

Conclusions

As a result, the SeaSonic Focus Plus Gold 750W SSR-750FX and 850W SSR-850FX power supplies appeared to be as good as the recently reviewed 550W and 650W models. The overall positive points remain the same: Compactness, modularity, kit, good cabling, efficiency even slightly higher than Gold certification, 10 year warranty and the fact that the units hold at least 25% overload.

Additionally, it was found that even in 50+ degree ambient temperatures, SeaSonic Focus Plus Gold can continue to operate, although this mode is not recommended. But as a fact they can, without shutting down on overheat protection. The 850 watt model becomes quite noisy when loaded with “full power. At the same time at 500-600W load it is quieter than the 550W and 650W models at the same load. True, we’re talking about a small noise delta.

To sum up the final verdict on the entire SeaSonic Focus Plus Gold line, we can only say that any of the models in the line are a good choice. Recommended for purchase.

Pros:

• Cute

• Compact

• Fully modular

• 10 year warranty

• Even though it is a medium-sized kit

• Gold-plated connectors

• Barely make it to Platinum certification

• Withstand up to 25-28% overload.

Cons:

• 850W model is a bit noisy at peak loads.