Review on Seasonic PRIME 850 Titanium SSR-850TR 850W 80+ Titanium Full Modular ATX12V & EPS12V Power Supply with 135mm FDB Fan, Power On Self Tester, and 12-Year Warranty by Justin Rasmussen

I wanted to upgrade my main computer from a mid-tower ATX case to something smaller. I finally settled on the SilverStone SG13 case as I was able to reuse most of my components. One thing I've had to change, though, is going from a full-sized ATX power supply to something a little less deep. SilverStone recommends that the ATX power supply should be no deeper than 140mm when using the SG13's drive cage. After a bit of research I found that the Seasonic Prime Ultra Gold power supplies are some of the best you can get if you have a smaller case like the SG13: 1) Its 135mm fan is not only a lot quieter than the 92mm fans used in small SFX power supplies but can move a much larger volume of air. 2) Prime Ultra's fan mode can be set to always run. This is very important in small cases where the power supply is used as an exhaust fan. The SG13 requires a constantly running fan as the air intake is located directly above the heatsink and CPU fan. 3) This PSU is fully modular so you don't have to look for places to stash extra cables in your case. .4) The absence of capacitors in the cable facilitates cable routing. It also makes it easy to plug in custom power cords if you decide to do so in the future. 5) Wires in ribbon cables can be separated individually. Initially I wasn't a fan of ribbon cables until I realized it's possible. This makes it much easier to bypass obstacles such as heatsink heat pipes. While I really like the way Seasonic designed this PSU, there are a few things I would change to make it even better: 1) Move the fan mode switch from back to front. Panel with cable connections. EVGA does this with their offerings and I think it makes more sense. This allows for more ventilation openings on the back and therefore better airflow through the PSU. 2) While the bezels on the side of the PSU look interesting, they don't work. If you look at the PSU from the side, you will see that they are covered with a transparent plastic partition. I understand that this plastic is needed to prevent accidental shorting of the case's internal components, but perhaps a small gap could be made to allow the shutters to work while protecting the internal components. When using this power bank as a range hood, every little thing counts when it comes to airflow and ventilation. 3) I'm guessing Seasonic was able to cram a 135mm fan into a 140mm PSU case, but I'm not entirely sure about the fan. Wahl, double wire, Hong Hua fluid dynamic bearing. Of course, a long warranty mitigates those concerns a bit, but you still have to deal with the downtime associated with shipping the power supply to a repair center and waiting for it to be returned. At this price I would prefer something like Nidec or Sanyo Denki. It's even better if it's a PWM with ball bearings, because they last even longer. Many power supply manufacturers advertise Japanese-made capacitors used in their power supplies. I think that should also apply to fan selection. 4) The hexagonal fan grille is a bit restrictive (see Puget Systems article "Impact of grille pattern on fan performance/noise"). The traditional wire mesh loses only 2% of airflow compared to 8% of the pressed steel hexagonal mesh. Wire mesh is also quieter. However, these are all small things that do not particularly distract from the power supply. All in all, if you want a fully modular power supply that fits into a compact case, I would have no hesitation in recommending the Seasonic Prime Ultra Gold. This device has a fatal error. The Hong Hua fan used in it makes a low rumble that is noticeable when you are in close proximity. I have a case on my desk and I noticed a specific noise after the hard drive stopped and went to sleep in the case. I opened the case and tracked the fan noise in the PSU. I'm attaching a video of me toggling the fan mode switch (it sets the fan to always or not) so you can get an idea of the noise. You may have to turn up the volume to hear it properly. Looking around on Youtube and other websites I'm not the only one with this problem. This also happens with previous Prime and Focus Plus modules. They all use the same fan supplier. In all other respects this power supply is great. However, the fan greatly distracts from his work. If you have a decently noisy system with multiple hard drives, you will most likely never notice the sound. If you have a system with an SSD and slow case fans and want to keep your computer quiet, you may need a different power supply. If Seasonic can fix the fan, it's a 5 star product.