Now it's time to crank up some heat. My hot box will help with that - it's an ATX case that has been modded to get the heat output from the SunMoon's exhaust fan ducted right into it. I've seen this thing hit 60 degrees in past test sessions on really big units. But because this is not a really big unit, I'll have to turn off the intake and exhaust fans in the box and hope that we see ambient temperatures high enough to make the Seasonic scream.

*Unit remained in fanless operation for duration of test

Well, I guess I'm the only one screaming in here, and it's due to excitement. In test two, the X650 is actually more efficient than it was cold, and even test five barely sees any drop. This platform is really outstanding when it comes to pure efficiency.

Know what else is outstanding? The fact that the unit was still fanless in my hot box. Sure, it only stayed off for test one, but let me be honest here - I've never had a fanless unit stay fanless in the hot box. It just gets too hot for most fanless units to stay that way.

And look - I did get the unit up to high ambient temps. Forty eight degrees, to be specific. Forty eight marshmallow roasting, butter melting, finger burning degrees, to be prolific. For-ty eig-ht de-gree-s to be sporadic. But look - the X650 didn't mind one bit. Why, it barely added any of its own heat to things, only hitting fifty nine by the time test five was over. For a while there, I thought the thermometer was faulty. Even better, the fan was barely spinning at all through the whole session.

Going back to the voltage readings, it only gets more awesome. But, slightly less awesome than that area was cold. The 3.3V and 5V rails are about as stable as they were cold, but the 12V has now lost its grip on that 1% number and is riding slightly above it here.

Let's take a look at the ripple and noise scope shots.

Oscilloscope Measurements - Seasonic SS-650KM
Test #	+3.3V	+5V	+12V
Test 1
Test 2
Test 3
Test 4
Test 5
Test CL1
Test CL2

Avert your eyes! The above shots are too awesome for human eyesight to tolerate! Yes, folks, this here Seasonic platform has decided to out-awesome just about everything I've tested to date. With ripple and noise under 20mV on all main rails from tests two to five, this unit joins the very best of the best for ripple and noise suppression. But, there's a bit of weirdness going on in test one on the 12V side of things. Must be a side effect of the design. Still, at 30mV for that test, there's nothing to complain about there, either, and it's unusual for a unit to actually get better here as the tests go along.

Now, I'm curious. I have to see what this thing looks like under the hood.