( Socket 478 - Pentium4 ) Rise Above Ambient Temp. (c)
Mfg.	Model	27mm large copper block		27mm large copper block
		50W		100W
Thermalright (high)	SLK-900U	11.6		20.5
Cooljag (high)	CJC66IC-A	10.4		21.3
Gigabyte (high)	PCU31-VH	12.5		22.3
Coolermaster (high)	Hyper6 KHCV81U1	12.4		23.4
Zalman	CNPS7000A-Cu	12.4		24.9
Thermal Integration	TI-RV104N	14.4		25.4
Alpha	PAL8942	14.7		26.1
Gigabyte (high)	3DCooler-pro	15.6		26.6
Coolermaster (low)	Hyper6 KHCV81U1	14.4		27.1
Zalman	CNPS7000-Cu	14.1		27.7
AVC	117140	15.2		27.8
JMC	401100	15.6		27.9
Coolermaster (high)	Jet4	12.6		28.1
Coolermaster	IHC-H71	14.0		28.1
Taisol	CEP447181	14.6		28.7
Jetart	JAP416A	11.8		29.1
Thermal Integration	TI-A8736N	12.4		29.1
Arkua	8568	15.4		29.3
Intel	Stock 3.06GHz	15.0		30.1
Jetart	JAP407A	13.8		30.2
Taisol	CCP445172	17.5		30.7
Thermal Integration	TI-RV108N	15.9		31.7
Spire	SP411C5	17.3		31.7
Arkua	Q85X-7J	16.7		31.9
Dynatron	DC1207BMX	17.2		32.4
Thermal Integration (high)	TI-V7035TN	18.1		32.7
Cooljag	JVC661A	17.3		33.5
TS Heatronics (6" fan dist)	NCU-1000	15.6		33.6
Dynatron	DC1206BMY	18.6		33.6
Scythe	Kamakaze	18.9		34.1
Zalman	CNPS6500-AlCu	17.2		34.3
Taisol	CEP426151A	19.4		35.4
Spire	SP420B8	17.4		36.2
Arkua	8456X-8T	18.6		36.3
Arkua	838T-7G	18.7		36.7
Intel	Socket 478	19.4		37.4
Dynatron	DC1207BMW	19.5		37.9
Zalman	CNPS5700D-Cu	18.9		38.3
Titan	CW9TB/SC	18.9		38.3
Evercool	NW9F715CA	19.1		38.5
Aopen	ACP4LC	17.9		38.8
Globalwin	VA476	20.8		39.3
Dynatron	DC1206BM-S	20.8		39.6
AVC	117160	20.3		39.8
Evercool	CUW8-715	21.8		40.8
Arctic Cooling	SuperSilent4 Pro	21.7		43.0
Dynatron	DC1206BMV	22.0		45.1
Vantec	GSN-7105	25.1		46.6
Arkua	848X-6B	27.3		53.2
Verax	P16	27.4		54.0
Dynatron	DC1U-B02	32.9		67.4
		50W		100W

Wow! The Coolermaster Hyper6 KHCV81U1 certainly makes a powerful high performance Pentium 4 cooling option when the fan speed is kicked all the way up to 3000RPM. Now while it doesn't quite rank in at the top spot, it is worthwhile mentioning that in the review of the Thermalright SLK900U we used the biggest baddest fan around - a 67.2 dB A loud Delta screamer! Whereas the Coolermaster Hyper6 ranks in 3-4 degrees Celsius warmer, it manages those temperatures at a more 'humane' 54 dB A noise level.

The other two heatsinks at the top of this reference list, the CoolJag CJC66IC (59.a dB A) and Gigabyte PCU31-VH (63.7 dB A) each were substantially louder, though the CoolJag heatsink was more in line with what we find here. When the fan speed on the Coolermaster Hyper6 is dialed down to ~1900RPM, it comes down a little in this temperature reference list - to the level of a high end heatsink - but with much better noise output.

Update: A lot of readers have written in to ask us to test the Coolermaster Hyper6 with the same jumbo Delta screamer which was used on the fanless Thermalright SLK-900U heatsink. FrostyTech typically only tests with the stock fan that ships with a heatsink, but to stem the flow of requests we went ahead and strapped on a 80x80x38mm Vantec Tornado fan. The thermal improvement was about 6-7 degrees, or more specifically, the rise above ambient temperature on the 100W test was just 17.9 degrees Celsius. This would place the Hyper6 at the top of this reference list, with a lead of 3 degrees over the SLK-900U. The down side is that the Vantec Tornado is about as loud as the real thing. :-(

At this time the FrostyTech 'System Mk.2' Athlon64 test bed is not quite ready, so we'll have to revisit the Coolermaster Hyper6 in the future, and see how it handles the heat when faced with the larger contact surface area of AMD's 64-bit processors. Stay tuned to FrostyTech for a special notice when we launch the improved K8 heatsink test platform!

Getting back to the Coolermaster Hyper6, while I'm sure you all agree the thermal performance of this large heatsink is exceptionally great, the acoustics could stand to be improved a few decibels. For starters, at the top of the heatsink where the 6 heatpipes come through the aluminum shroud, I'd highly recommend adding some epoxy to stop the rattling, and vibrations in the aluminum component. Ideally, a couple of rubber gaskets would work wonders for A) absorbing any fan vibrations, and B) preventing metal-to-metal contact noise. I'm almost tempted to drill out the swag joints that hold the Hyper6 fan shroud in place and add some rubber washers around each of the heatpipe tips at the top... but perhaps Coolermaster will take this small criticism to task and initiate a quick revision themselves?

The retail price for the Coolermaster Hyper 6 heatsink is currently not known, but I'd expect it to be pretty competitive given Coolermaster's history. In any event, the bottom line remains that the Coolermaster Hyper6 KHCV81U1 is one heck of a Pentium/Athlon64 heatsink. While it easily ranks alongside the cream of the performance heatsink crowd, it is a bit quieter than the top heatsinks listed in our comparison chart. A massive hunk of copper with six heatpipes basically says it all, and with thermal performance to match, what more could you ask for?!

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Here are a few other articles that you might enjoy as well...

1. Thermaltake Silent Boost A1889-01 Copper Heatsink
2. Gigabyte 3DCooler-Ultra PCU31-VH P4/K7/K8 Heatsink Review
3. Coolermaster Jet 4 ICB-V83 Pentium 4 Heatsink
4. Scythe Kamakaze AthlonXP / Pentium 4 Heatsink Review
5. Thermal Integration TI-RV108N Pentium 4 Heatsink
6. Cooljag CJC66IC-A Copper Pentium 4 Heatsink Review
7. Thermal Integration TI-A8641L Heatsink Review