The YS-Tech fans are as noisy as your average 60mm Delta, so be wary of using this heatsink in any applications where noise would be an issue. To hear for yourself first hand, we have included an MP3 recording about ten seconds long of the heatsink in operation. To listen to this heatsink, just clip on the headphones!

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	Thermal Integration	TI-V77L	26.5	39.1	44.4		57.5	63.6	grey	1	med	med
2	Thermal Integration	TI-S8640N	21.4	38.3	42.9		52.8	64.4	grey	1	loud	med
3	Vantec	CCK-6027D	27.4	45.4	49.6		64.9	73.4	none	1	med	med
4	OCZ	Dominator	26.5	37.7	50.9		52.4	74.2	none	1	loud	med
5	Swiftech	MCX370-0A	22.3	42.0	46.1		60.3	75.6	none	1	med	hard
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	Thermalright	CB-6L	24.6	50.3	57.7		73.8	92.7	white pad	1	low	med
10	Fortis	A92	26.7	45.6	65.8		67.8	97.8	none	1	loud	stiff
				50W	50W		100W	100W

Initially, the results of the TI-S86 appear to be very close to that of the substantially more squat TI-V77L heatsink with its copper core. From the results you can see there is a tendency for this heatsink to work better on the larger interface die, than on the smaller one. Chances are that the extra height of the TI-S8640N is the main reason for this, as there is more heatsink to absorb the heat flux from the larger core. Note that all of the top four heatsinks are very loud. The Swiftech uses a Papst fan while is a bit quieter than the rest.

Rise Above Ambient Temp. (c)
	Mfg.	Model	27mm large copper block	15mm small copper block		27mm large copper block	15mm small copper block
			50W	50W		100W	100W
1	Thermal Integration	TI-V77L	12.6	17.9		31.0	37.1
2	Thermal Integration	TI-S8640N	16.4	21.5		31.4	43.0
3	Vantec	CCK-6027D	18.0	22.2		37.5	46.0
4	OCZ	Dominator	11.2	24.4		25.9	47.7
5	Akasa	Silver Mountain	19.6	24.9		38.4	49.5
6	Vantec	CCK-6035D-Retail	17.7	26.3		36.7	51.4
7	Swiftech	MCX370-0A	19.7	23.8		38.0	53.3
8	Thermaltake	Volcano 6cu+	13.8	28.8		32.1	57.9
9	Thermalright	CB-6L	25.7	33.1		49.2	68.1
10	Fortis	A92	18.9	39.1		41.1	71.1
			50W	50W		100W	100W

As we thought, the performance of the TI-S8640N on the larger interface die is much better than on the small die, and apparently better than most of the other coolers on the list of reference coolers. Despite the size increase of the heatsink I would also suspect the exhaust direction from the fan plays a significant part in these rather compelling temperature numbers.

Overall, the TI-S8640N offers very good competition to that of the 70mm TI-V77L and its' oh so fabulous copper slug. Definitely a good heatsink to use if you stumble across one in the local computer store. Remember though that noise levels may be an issue with this heatsink in a room, or area where quiet is important.