Seasonic X-650 KM3 650W Power Supply

Every so often, a power supply arrives in the lab that fills my heart with anticipation and high expectations. Today, we’re looking at just one of those units – Seasonic’s updated and revised X-650 unit. The design has been freshened up with such things as a switchable semi-fanless mode. Let’s see what else has changed.

PRODUCT: X-650 KM3 650W
PROD LINK: X-Series Product Page
PRICE: $139.99 @ NewEgg
Price is at the time of testing!

Awwwww yeah! Got ta got ta! Yep yep!

I’m not just quoting a Vanilla Ice cover of a Wild Cherry song for no reason people, I’m doing it because I’m genuinely excited about getting started on this week’s review sample. That’s right, folks, I have another Seasonic up on the load tester today. This time, I’m looking at their updated “KM3” version of their successful X series 650 watt unit.

As was the case with the older units, this one is certified 80 Plus Gold. If other recent Seasonics have been any indication, we should be in for something very special indeed.

But before we get to the load testing to see what’s changed for the X series in this new revision of the platform, we need to get some box pictures out of the way. Mr. Fuji, zoom in if you please.

Nothing new here for Seasonic… the X series has been using the VRM approach and the same fully modular connection ability since inception. I’d expect that these features would carry over.

Again, nothing unusually new here.

We get the same fan control modes we’ve seen on other recent Seasonic units too, it seems. A switch to flip between semi-fanless and fully fanned mode.

You may recall that the original X series units didn’t have this feature.

Seasonic is still using Sanyo Denki for fannage.

Specs! Connectors! Safety approvals!

Once again, in case you don’t speak English, Seasonic’s translated the features to other languages here.

Bah… enough of the box. Let’s unpack.

Inside the box, we find a user manual, warranty sheet, power cord, bag of modular cables, a bag of accessories, and a velvet bag of power supply.

The contents of the accessories bag. We get the usual stuff from a Seasonic retail unit, it seems.