FrostyTech has posted a review on the Arkua 7528 Copper-Core Heatsink
Where the model 7228 has a speedy 60mm x 25mm 6800RPM fan the 7528 has a 70mm x 15mm 5400RPM fan. From the users perspective, the 7528 is quieter, and offers comparable performance because it is based on the same underlying metal fin assembly.Read more
We all know that fan power plays an important role in cooling so the real question now becomes, how much of a difference is there between the two Arkua coolers? The 7528 is an aluminum heatsink with a copper slug for a heart. With the copper core, a more thermally conductive center (28mm in diameter) will tend to move the heat to the surrounding aluminum faster. The top of the copper slug is exposed, and you can almost wonder why Arkua didn't cut any fins in the surface like the Dragon Orb from Thermaltake. In cany case, the base which interfaces with todays largely bare silicon processor dies is machined nice and smooth.
