Its getting hard to think up an clever thing to say with so many fans that are essentially 60mm Delta's. So... if you want to hear for yourself just click on the pair of headphones below.

Synthetic Temperature Test Results: *Ranked according to 100W small interface die test results.

FrostyTech Synthetic Temperature Test Platform Results
	Mfg.	Model	Ambient Temp.	27mm large copper block	15mm small copper block		27mm large copper block	15mm small copper block	Thermal pad	No. Fans	Fan Noise	Clip force
				50W	50W		100W	100W
1	Arkua	7228	23.1	37.3	39.4		52.0	57.2	none	1	loud	easy
2	Thermal Integration	TI-V77L	26.5	39.1	44.4		57.5	63.6	grey	1	med	med
3	Coolermaster	HCC-002	22.0	41.0	45.8		54.6	66.3	none	1	loud	easy
4	Vantec	CCK-6027D	27.4	45.4	49.6		64.9	73.4	none	1	med	med
5	OCZ	Dominator	26.5	37.7	50.9		52.4	74.2	none	1	loud	med
6	Akasa	Silver Mountain	26.6	46.2	51.5		65.0	76.1	none	1	loud	med
7	Vantec	CCK-6035D-Retail	26.5	44.2	52.8		63.2	77.9	none	1	loud	med
8	Thermaltake	Volcano 6cu+	26.5	40.3	55.3		58.6	84.4	carbon	1	loud	med
9	Spire	5T060B1H3R	26.7	42.7	57.5		64.6	85.1	none	1	low	med
10	Fortis	A92	26.7	45.6	65.8		67.8	97.8	none	1	loud	stiff
				50W	50W		100W	100W

I had expected the Arkua and Thermal Integration heatsinks to come in at about the same level, but the Arkua would have nothing to do with that. Compared to the other reference coolers it just blows away the competition. Remember that while the Arkua and Thermal Integration coolers look similar from the outside they are not exactly the same. The full height of the Arkua is not taken up by the copper core, but rather, the fins continue to extend upward.

Thermoengine played around with similar technology if you can think 6 degrees aside. Where they had a hollow center, Arkua use a cut out region. At the time the best explanation of why the Thermoengines had that hollow center revolved around lowering the thermal mass of the entire body (Joe from Overclockers said this I think). The Aruka technique is along similar lines, but is easier to manufacture, and even makes engaging the clip a more straight forward.