360° View - Coolermaster Nepton 280L - Water Block Information on Frostytech's test methodology is available here.
The Nepton 280L waterblock stands 48mm tall, with a foot print of 70x75mm. Pump power is supplied by a 3-pin motherboard fan header and the Coolermaster logo is illuminated by white LEDs as a visual indicator of pump status. Both of the 15mm OD 90-degree pipe connections fully swivel. The Intel and AMD metal mounting brackets attach with two screws each, so installation is very simple.
The pump head is roughly 70mm square, not including the metal AMD/Intel brackets when they are attached. Below the black plastic bezel, the actual waterblock frame is a single piece of robust grey plastic which you can see poking out the bottom if you look closely. Notice the larger diameter FEP tubing used on the Nepton 280L system.
The copper base plate measures ~1.3mm thick and is approximately 63x57mm. Anti-tamper triangular head screws prevented us from taking a close look at the Nepton 280L's micro skived copper plate.

360° View - Coolermaster Nepton 280L - Heat Exchanger Information on Frostytech's test methodology is available here.
	The 30mm thick aluminum heat exchanger used with the Nepton 280L measures 311x140mm in size and supports a pair of 140mm fans mounted side-by-side, or 120mm fans.
Mounting holes are provided for 120mm fans as well in case you need to connect the heat exchanger to a smaller 120m PC chassis fan vent, or wish to use four 120mm fans.
	Fans can be attached on either side of the heat exchanger. The 15.5mm O.D. FEP tubing is connected to metal barbs that do not swivel. The fill valve is not user accessible.
	The fill valve is covered by a warranty sticker to prevent end users from contaminating the coolant supply inside.

Base Finish and Flatness

Flipping a heatsink over to inspect the business end is often a simple indicator of overall cooler quality. More practically speaking, a heatsink is in many ways only as effective as the contact it makes with the processor - the flatter and smoother the better. Base finish is one of the criteria that Frostytech measure in the course of evaluating heatsinks, and it involves two distinct aspects. Surface Finish is the first; this is calculated with the aid of Surface Roughness Comparator that has a cross section of common machine surface finishes and their numerical surface roughness equivalents in microinches. The second is Surface Flatness. This is tested with an engineer's straight edge or proven flat surface, in two axes.

The copper base plate of Coolermaster's Nepton 280L waterblock has a fine-sanded surface finish with a surface roughness of approximately ~32 microinches. The copper base plate is very slightly convex in one axis and just about perfectly flat in the opposite. The copper base plate must be flexible as thermal compound squeezed out completely during testing, indicating flush contact with our flat copper CPU interface die.

Next, acoustic measurements and then AMD and Intel synthetic thermal test result charts.