Seasonic X-Series 750W: Potent for the Price
by Martin Kaffei on April 13, 2010 11:13 PM EST- Posted in
- Cases/Cooling/PSUs
- Seasonic
- PSUs
X750: Potent for the Price
With the X-series, Seasonic delivers an outstanding performance. It's not only the high efficiency but also the good voltage quality and EMI friendly topology that make the X750 one of the most interesting power supplies on the market. With its double-sided circuit board, Seasonic sets the bar quite high and the semi-passive cooling will be great for users that frequently run at sub-50% loads. While the Enermax Pro87+ and Modu87+ are quieter at high loads, they're noisier at lower loads and still audible at sub-20%; with the fan shut off below 20%, the X750 is truly silent at low loads. Furthermore, the Sanyo Denki fan is a high quality design and should last a long time; the classical ball bearing is out of style and Enermax chose its Twister models wisely.
The selected line filtering stage from Yunpen is an excellent choice for interference suppression during relatively low loads; many manufacturers try to save money here in order to cut down resistance, which prevents optimizing the efficiency. Even though they are not necessary for a good thermal solution, it's good to see the continuing usage of Japanese capacitors. The 105 °C variants last a very long time and there are plenty of capacitors on the secondary circuit to provide good voltage filtering. While the idea of integrating a DC-to-DC converter with the cable management PCB may not have been their own, in practice it works well and their implementation is very good. Overall, the processing and soldering quality are very clean and the build quality is top notch.
In terms of connectors, the X750 is well equipped. Users get four 6/8-pin PCIe connectors and eight SATA/Molex connections, allowing for a wide spectrum of HDD/DVD/fan configurations. Only triple-SLI computers would need more connectors, and we wouldn't recommend running such a system off a 750W PSU—and we wouldn't generally recommend 3-way SLI at all. For modern GPUs like GF100/Fermi (GTX 470/480) and Cypress (HD 5850/5870), the X750 will work well, though SLI with Fermi will need a larger PSU. The cable sleeves are well done and help keep everything looking neat and organized, as does the fully modular cable system. What would help now would be some aftermarket cable packages for users that need/want longer or shorter cables, but even without those the modular cables will make this PSU simple to install in a case. The dimensions of the X750 are also small considering the rated output.
The DC-to-DC converter and high voltage output on the +12V rail makes the X750 a great fit for users running quad-core processors with SLI or CrossFire GPUs. However, if you have an older system you won't need to worry as 125W on +3.3V and +5V are still more than adequate. On 230VAC grids, the Seasonic X750 reaches up to 91% efficiency, but even on 115VAC the 89% efficiency result is nothing to sneeze at. [Gesundheit!] The relatively large voltage drop on the +5V rail is a minor point of criticism, but the 5V rail isn't particularly important for a modern system. The small amount of ripple is very welcome, and the resonant topology reduces ripple at high load.
Seasonic started out building PSUs for a lot of other companies, but these days they're focusing more and more on end users. With improved build quality and aesthetics, a 5-year warranty, and a very competitive price they have a lot on their side. The X-Series is everything you would expect from a modern 80 Plus Gold certified power supply. It will work great with anything from entry level PCs up though high-end SLI/CrossFire systems. The only thing missing from the X-Series are products targeting moderate users (i.e. sub-500W PSUs) as well as 1000W+ behemoths suitable for running GTX 480 SLI.
The Seasonic X750 is available starting at $170 (150€), so as usual quality doesn't come cheap, but the current price is $50 less than the competing Enermax Modu87+ 700W and still less than the non-modular Pro87+ 700W. With similar qualities and performance (we'd give Enermax a slight edge in overall performance), the price gap makes the X750 is an easy recommendation if you have to decide between the two. However, if you're planning on running at higher loads, Enermax can do so without generating as much noise.
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Londeninfo - Wednesday, September 7, 2011 - link
My pc psu have been causing troubling me from many days. Whenever I touch the CPU i feel the electric shock.I cant figure out the problem!!!!<a href="http://www.londeninfo.com/">Londen</a&g...
Londeninfo - Wednesday, September 7, 2011 - link
<a href= "http://www.londeninfo.com" > Londen </a>Earthmonger - Wednesday, April 14, 2010 - link
Is it okay if I use this review to comment on something I'm getting really tired of seeing in upper class power supplies? It is? Thanks.[quote=Martin Kaffei]The cable sleeves are well done and help keep everything looking neat and organized, as does the fully modular cable system.[/quote]
This. These cables are not well sleeved. Every time I see bare wires on these expensive new units I roll my eyes, and add $40 to the end cost, since I'll have to completely re-sleeve all cables. It's awesome (seriously) that they're going fully modular these days, but for the price premiums, you'd think they would care more about the details.
bigboxes - Wednesday, April 14, 2010 - link
How anal are you? If you must cover the last 1/4 inch of wires where they meet up with the connector why don't you just use some additional shrink tubing?Minion4Hire - Wednesday, April 14, 2010 - link
Yea, what's the big deal? To my understanding one of the reasons they don't sleeve them to the very ends is to allow greater flexibility and bends in the cable to help make installation easier, which can be especially useful in smaller chassis. The shrink tubing at the end of the sleeve isn't exactly flexible, and would and would "pad" the back of the connectors by several centimeters if they were butting up against it. Better for the cables? Potentially. But I'm willing to bet that the average person would find it to be that much more painful and annoying during installation.Earthmonger - Wednesday, April 14, 2010 - link
Quite anal, yes. If a wire isn't completely sleeved, it shouldn't be sleeved at all. It just feels half-assed.As for the reduction in flexibility, not all heatshrink is rigid. I have some laying around here that is soft and pliant. Nor does it take several centimeters of heatshrink to do the job.
I do prefer individually sleeved cables though. Wire clusters aren't flexible enough, whereas I can bend a flat double-row of individuals right around a 90 degree without issue.
7Enigma - Wednesday, April 14, 2010 - link
What a poor comment. The purpose of sleeving is for better air flow and easier access to components. The terminal ends are kept free for better connectivity.You can glitter up your case/components all you want to satisfy the anal inner-you, but for the rest of us, I think we find this more than acceptable sleeving.
bigboxes - Wednesday, April 14, 2010 - link
I know what you are talking about. I just find you are a tad unrealistic. If you want bling then maybe you're looking at the wrong mfg. Seasonic is for the enthusiast. It's fairly plain, but well built and engineered. I prefer function over form and I still think it looks good. Of course I don't have a window or lights in my case. I like quiet. I have sleeving mesh and shrink tubing, but the sleeving on this unit (and all Seasonic PSUs) is top notch. I have sleeved up to (and even over) the connector before. I just think you are asking too much from the mfg in this case. Sounds like you are going to redo whatever someone else does because you have certain tastes that only you can live up to. And that's tottally understandable. I'm sure most people think I'm too anal over my builds too. :)HOOfan 1 - Wednesday, April 14, 2010 - link
If I saw bare wires...I would stay very far away from the PSU...talk about short circuits....Luckily, these wires aren't bare, they are covered in plastic isulation.
Smartass remark out of the way, there is no way to extend the sleave all the way to the end, the wires would have to be individually sleaved, or done like the flexforce cables...individually sleaving them would raise the price exponentially.
MrSpadge - Wednesday, April 14, 2010 - link
What an amazing comment!(1) you need to spot the "missing" sleeve at the end of the cables
(2) you have to recognize it as something you don't like
(3) you have to seriously consider fixing it for 40$ in case you'd want to buy this PSU
I'm not sure anyone else on this planet could fulfill all 3 ;)