FrostyTech posted a review on the Akasa AK-873 AMD Athlon64 Heatsink

Over the years we've seen aluminum heatsinks migrate to copper, and then heat pipes slowly began appearing here and there. The first heat pipes were added on as afterthoughts, and then thermal designs caught up with the technology. Now, what we're seeing is a shift from multiple 6mm diameter heatpipes to a reduced number of larger, 8mm diameter heatpipes. There will be more coolers arriving on the market place with this method of enhanced heat transport, but the Akasa AK-873 is clearly one of the first to cross our test bench.

Akasa AK-873 Heatsink Review