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
Thermalright	SLK800	21.7	34.8	37.5		45.2	51.6	none	1	loud	med
Thermalright	AX-7	21.7	34.8	37.1		46.1	52.1	none	1	loud	med
Tocools	Novasonic-AlCu	20.1	33.1	37.9		49.3	53.0	none	1	med	easy
Tocools	Novasonic	22.9	40.9	39.9		54.4	59.4	none	1	med	stiff
Coolermaster (high)	ASBV73U1	25.5	38.9	43.6		50.2	62.2	none	1	loud	easy
Coolink	U1P2	26.1	39.4	44.9		50.9	62.2	none	2	loud	easy
Arkua	628	23.9	42.7	42.1		58.9	62.3	none	1	med	med
Thermal Integration	TI-V77L	26.5	39.1	44.4		57.5	63.6	grey	1	med	med
Sibak	AC02625B	23.2	41.3	59.0		43.2	64.7	none	1	loud	med
Thermalright	SLK-900A	20.6	37.4	44.0		55.1	65.5	none	1	low	easy
Sibak	AC06725TH	22.5	42.9	46.2		61.7	67.7	none	1	Very loud	med
Coolermaster	HHC-001	21.7	40.0	44.8		56.3	68.1	none	1	loud	easy
AVC	Tundra2	22.0	41.4	47.5		59.0	71.1	none	1	loud	stiff
Thermalright	SK-7	19.9	39.2	42.7		57.8	72.0	none	1	low	easy
Aopen	ACK7L	21.4	43.4	47.2		62.6	73.2	grey	1	low	easy
Scythe	Kamakaze	20.7	39.6	47.9		54.8	74.3	none	1	med	hard
Coolermaster	HSC-V62	21.4	47.4	52.8		61.7	74.5	none	1	quiet	easy
Arkua	728M-7N01	20.8	40.5	47.8		60.5	75.8	metal	1	med	easy
Spire	5F263	22.6	44.7	51.8		64.3	76.2	white	1	low	med
Taisol	CGK760092	23.4	42.7	51.3		61.2	77.5	pink	1	low	med
Zalman	CNPS6000-Cu	24.8	46.4	53.8		65.6	78.2	none	1	very low	easy
Titan	TTC-CU9TB/SC	21.9	43.7	49.9		63.5	78.8	none	1	loud	easy
AVC	112AM1	24.8	46.6	52.9		70.1	79.6	none	1	low	stiff
Thermalright	SK6+	21.1	38.2	51.7		54.4	79.9	none	1	med	easy
Taisol	CEK787172	21.5	38.4	53.5		57.3	82.0	PCM45	1	med	easy
nPowerTek	TTIC NPH-2	20.6	35.2	50.3		60.6	82.5	none	1	med	easy
Titan	D9TBCu35R1	21.5	44.5	53.2		68.7	83.0	none	1	med	easy
Spire	5U213C1H3G	19.8	45.8	54.4		67.1	83.3	pink	1	low	easy
Spire	SPA04B4	21.5	45.9	55.1		70.1	86.6	none	1	low	easy
ArcticCooling	CuSilent2	20.1	42.7	57.4		68.1	86.7	none	1	low	med
Verax	P14Cu	25.5	51.3	57.4		75.2	88.7	white	1	silent	easy
Akasa	AK821	22.7	49.4	57.2		74.1	93.2	grey	1	med	med
Verax	P11T	26.1	61.2	69.7		90.9	102.7	none	1	none	easy
			50W	50W		100W	100W

The other Thermalright heatsinks we tested recently were able to rank in a little higher in this list of reference heatsinks. The Thermalright SK6+ is showing its age, and coupled with a stock 60mm fan doesn't look like it has the necessary mix of thermal dynamics to do very well...

It would seem as the glory days of the Thermalright SK6+ are long gone. While the heatsink managed to dish out some decent thermals on the 100W small interface die test, it's really no match for performance cooling anymore.

What does this tell us then of pairing a stock 60mm fan with the SK6+? Well, while the Thermalright SK-7 managed to perform pretty well with a stock 80mm fan, the SK6+ just doesn't have the size to dissipate the heat fast enough.

The design of the SK6+ was good for its day, but now is really just relegated to the cooling that old Athlon in your file server. I'd hoped that the SK6+ would have been able to reinvent itself as a low noise heatsink with the right fan, but that's about all it has been able to manage... and at 50dBA there are far quieter options in the reference list to choose from.