How To Build a Water Cooled Mini-ITX SFF PC w/ Ivy Bridge & Kepler

Cosair AX 650 – 80 Plus Gold PSU

For this build we had pretty specific requirements that we put in place for the power supply. We wanted a power supply that was around 650 Watts and fully modular to reduce clutter and improve airflow inside the case. We also wanted a very efficient power supply, so that meant at least 80 PLUS Gold rated. To be 80 PLUS Gold certified it means that the power supply must be at least 90% efficient at 50% load and 87% efficient at 20% and 100% load. Fortunately for us, the list of fully modular power supplies that are 80 PLUS Gold certified isn’t that long!

The Corsair AX650 power supply is one of the highest-quality mid-wattage power supplies on the market today and it met all the requirements we had when it comes to the power supply needed for this build. The Corsair AX650 is fully modular, 80 PLUS Gold rated and comes backed by a 7 year warranty.

The Corsair AX650 PSU has a single +12V rail that is rated at 54A, which is more than plenty for our build. With the Intel Core i7-3770K and EVGA GeForce GTX 670 Superclocked video card in the system we figured power usage will be around 200-250 Watts at full load. This means that we will only be using 7-35% of the power supply’s potential, which has both pros and cons. The pro is that we have plenty of room to grow, but the cons are that we are below the power supply’s peak efficiency range (50%) and the fan will never kick on.

The fan in the Corsair AX650 only kicks in when the ambient temperature reaches a certain point or the PSU hits a 50% load rating. We’ll never be close to that, so this power supply will be basically fanless and never make noise in our system!

The Corsair AX650 Professional Series Gold PSU measures 150mm(W) x 86mm(H) x 160mm(L), but for some reason would not slide into the Cubitek Mini ICE the way it was supposed to. We contacted Cubitek and they had this to say:

“Our Product Manager confirmed to that this mini-ITX case was not designed for such PSU with large fan grills. Even mini-ITX cases from competitors (e.g. Lian Li) do not support such large PSU for sliding in and you can’t find anybody complaining about it. Supporting this PSU format does not make sense to us as the case would get too big. Hope you can understand our design reason and won’t take this as negative point, buyers just have to be aware what components to buy for a mini-ITX case.” Cubitek PR

The ATX Standard has been around since 1995 and ATX power supplies generally have the dimensions of 150mm(W) 86mm(H) 140mm(L) with common mounting layout of four screws arranged on the back side of the unit. This Corsair PSU model is a little longer, but has a fan grill that sticks up a little bit. Corsair doesn’t put the extra fan grill height into their dimension specifications for some reason, so we will pass the blame along to them. Most power supplies will fit into this opening.

We installed the PSU bracket on the back of the case and mounted the power supply like normal and it fit fine, albeit very tight. There really is no place to hide the wires in this case, so we tucked them the best we could below the video card and to the left of the fans. We could have put them below the power supply and above the motherboard, but we wanted to keep that area open so some air could flow over the board.