In recent months we've tested a few heatsinks from a company by the name of Eumax. Of the heatsinks we've evaluated, there has been a surprisingly large variance in the build quality - perhaps hinting to some poor out sourcing choices for certain past models. While the majority of the Eumax heatsinks we have tested have been well made, there was at least one model which drew ire from us. That model was the EU01, and if you'll recall, it was a copper fin that spontaneously dropped out of the heatsink during testing that caused concerns.

Luckily, that appears to have been an isolated failure in Quality Control on the part of the manufacturer, as the Eumax heatsink we are testing today is definitely up to snuff.

The Eumax B605-01 comes to us from the folks at Iocombo.com, and it appears they're not about to settle for bum coolers. The Eumax B605-01 is a full copper heatsink which has received a nice nickel plating for that shiny, "I'm gonna get you sucka!" look that makes toasty AMD AthlonXP heatsinks quiver with fear. Or, at least that is the way it's supposed to go.

	Heatsink Specsheet: Model: B605-01 HS Material: copper, nickel plated Fan: 12V, 0.40A Fan Dim: 15x70x70mm FHS Dimensions: 44x72x70mm Made by: Eumax Sold By: www.eumax.com

In reality the plating is not going to improve cooling for the solid-copper heatsink; what it will do is prevent the copper from oxidizing over time, and the smooth surface can help cut down on dust accumulation to a small degree. A smooth surface doesn't seem to "grab" dust as easily as other treatments, especially at the edges of the punched out copper fins. There are a few other things the plating may do to help the interface between the base and fins, but it is difficult say for certain what the overall thermal impact will be.

Eumax B605-01 Heatsink From All Angles
	The Fan: There isn't anything particularly special about this 70mm fan which supports RPM monitoring except for the fact that it draws 0.4A. Most fans this size will only pull in 0.2A and rotate at 4500RPM. The fan mounts directly to the fan shroud which is part of the heatsink body, and apparently nickel-plated copper as well. The nine-bladed impeller has a motor diameter of 32.5mm in diameter.
	Heatsink Top: The fulcrum for the clipping mechanism is off-center as it is supposed to be according to AMD spec, this ensures that force is applied over the core, and not the center of the heatsink base. Interestingly, the three-prong clipping mechanism has not tabs jutting out at the fulcrum to lock the copper heatsink in place and prevent it from sliding down over time despite the fact that the heatsink is built for that. A circular hole is cut in the fan shroud which supports the base of the fan the customary 4mm above the tips of the cooling fins.
	Side A: The base of the heatsink measures 62mm x 60mm in size but since the fan is 70mm square the shroud extends out to support it. Given the size restrictions of the socket A platform, this is a quick and easy solution to install a larger sized fan on the heatsink without potentially interfering with adjacent capacitors. The overall height of the heatsink itself is 28mm, the fan adds another 15mm to the entire profile.
	Side B: The three-prong clip requires a screw driver to engage, and the also helps to distribute the clipping load over a wider area so it is less likely that the socket itself will fail. The copper fins are punched out and joined with a mechanical interlocking tooth to form one solid unit, with equal spacings of 1mm. The fins each measure 0.3mm thick, and the base 4mm. There are 18 fins in each group measuring 20mm in height.
	Heatsink Base: To test out a base we use a thin straight edge silhouetted in front of a light. Any light that pokes through tells us there is a gap, depression, or slight curve to the base of the heatsink. The critical area is where the processor core comes into contact with the metal, but it's always nice to see a totally flat face over the entire base plate. The Eumax B605-01 has a pretty flat surface in one axis, and a very shallow depression in the other (to shallow to cause any problems with the small die of an AthlonXP). Because of the plating the copper has received, the surface is smooth to the touch.