Seasonic PRIME Ultra 1000W Power Supply Review

Author:Paul Johnson

Editor:Kyle Bennett

Date: Monday , July 09, 2018

The Seasonic PRIME Ultra 1000W is angling to be the "best" 1 kilowatt computer power supply ever built. It boasts having some of the best power efficiency and delivery on the market, all while delivering features like being fully modular, a fully silent mode, and Seasonic's 12 year warranty.


The first thing we are going to look at with the PRIME Ultra 1000W is its packaging, accessories, and documentation. While normally none of these items is a make or break item for a power supply the packaging quite often contains a lot of information about the product we are purchasing. The inclusion of an owner’s manual that provides actual information about our product is also of great help. Accessories are almost unnecessary with a power supply as the unit is self contained, unless it is modular, but there are cases where a manufacturer can include useful accessories to make installation, routing, and use more efficient.

The PRIME Ultra 1000W packaging is similar to what we saw from the PRIME Ultra 750W which probably comes as no surprise. Once again, the front of the packaging lacks pictures. Instead, we see a huge shiny swath of silver on a patterned background with only two points of interest. The first being the 80 Plus Titanium seal and the second being the listing for a 12 year warranty. A brief check of the 80 Plus website does indeed find this unit certified for 80 Plus Titanium levels of efficiency (we will see how this unit does in that respect a little later on). The warranty is also interesting as, at 12 years, it is one of the longest warranties offered that we have seen. When we flip to the rear of the packaging, we find a bunch of advertising about the unit along with a picture of the power supply. One of the interesting notes here, much like was the case with the PRIME Ultra 750W, is that the product does not say "Made in Taiwan" like the original PRIME series units. Perhaps that is because it is expected at this point or, perhaps, because this unit is made in China (aka People’s Republic of China) not Republic of China (at Seasonic’s factory there) like the vast vast vast majority of power supplies that you see reviewed here (and in general use in the consumer realm). Moving on to the sides of the packaging, we find the power label (reproduced below) and the connector counts (reproduced below).

The PRIME Ultra 1000W is advertised as being a single 12v rail power supply similar to what we have seen from other PRIME units and most Seasonic units in general. Like with the previous 1000W PRIME unit, today's PRIME Ultra 1000W 12v rail has a capacity of up to 83A (or ~99% of the unit's capacity) if necessary. The minor rails (5v and 3.3v) each have a capacity of 25A and the combined capacity of those two rails is 125W. Combined with these outputs, we find that this unit has 8 PCIe connectors, 14 SATA connectors, and 5 Molex connectors. From a connectivity standpoint, this unit is better appointed than we have seen from previous 1000W PRIME units by just two SATA connectors. In general, most people will find this arrangement more than satisfactory.

Once we open the PRIME Ultra 1000W packaging, we are left looking at the PRIME Ultra 1000W itself, a power cord, some screws, the modular cables in a pouch, some zip-ties, some Velcro straps, the power supply "tester" (it is essentially just a jumper), an installation guide, and a pair of user manuals. As before, the user manuals are 20 pages long in 9 languages for one and 40 pages long in 10 languages for the other. The user manuals include installation instructions that are found in the separate installation guide as well for some reason, warranty information, troubleshooting steps, and cabling specifications for the entire line of PRIME units. The electrical specifications of the unit are again sparse so that aspect is not great. Overall though, things look like what we saw with the previous PRIME Ultra entrant so let's move on to look at the unit itself now.