Seasonic PRIME Ultra 750W Power Supply Review

Author:Paul Johnson

Editor:Kyle Bennett

Date: Monday , January 15, 2018

This new Seasonic PRIME Ultra 750 watt computer power supply is a revision of its previous PRIME Ultra line of PSUs. This alone makes us wonder just how much better Seasonic can actually make these power supplies, given just how great these were last time around. Let's find out if Seasonic has achieved building an even better PSU.


The first thing we are going to look at with the PRIME Ultra 750W 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 750W packaging is immediately familiar to anyone who has seen a PRIME unit from Seasonic before. Once again, the front of the packaging lacks pictures. Rather, users are greeted by a huge shiny swath of silver on a patterned background. In this field of silver we only find 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. The warranty is also interesting as it represents a two year extension over the previous 10 year warranty offered with the first PRIME 750W unit we saw. 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 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 750W is advertised as being a single 12v rail power supply similar to what we saw from the previous Prime 750W we reviewed from Seasonic. Once more, we see a unit that has a capacity of up to 62A (or ~99% of the units capacity) on the 12v rail if necessary. The minor rails (5v and 3.3v) each have a capacity of 20A and the combined capacity of those two rails is 100W. Combined with these outputs, we find that this unit has 4 PCIe connectors, 10 SATA connectors, and 5 Molex connectors. These values represent a match for what we saw with the previous Snow Silent 750W and PRIME 750W so this unit is certainly on par with its predecessors and these numbers seem about right for this product and market segment today.

Once we open the PRIME Ultra 750W packaging, we are left looking at the PRIME 750W 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. 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 for some reason, warranty information, troubleshooting steps, and cabling specifications for the entire line of PRIME units. What we don’t get this time is much in the way of the electrical specifications of the unit. So, this bit of documentation is probably a bit worse than what we saw from the previous PRIME units. Let's move on to look at the unit itself now.