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

FrostyTech Synthetic Temperature Test Platform Results
Mfg.	Model	Ambient Temp.	27mm large copper block		27mm large copper block	Thermal pad	No. Fans	Fan Noise	Clip force
			50W		100W
JMC	401100	19.5	35.1		47.4	grey	1	med	easy
Zalman	CNPS7000-Cu	21.0	35.1		48.7	none	1	low	easy
Taisol	CCP445172	20.2	37.7		50.9	none	1	med	easy
JMC	400074	19.5	37.3		50.9	grey	1	med	easy
AVC	117140	22.6	37.8		50.4	none	1	med	med
Coolermaster	IHC-H71	23.0	37.0		51.1	none	1	loud	stiff
Arkua	8568	22.4	37.8		51.7	none	1	med	med
JMC	400124	19.5	36.6		52.1	none	1	med-low	easy
Thermal Integration (high)	TI-V7035TN	20.2	38.3		52.9	none	1	very loud	easy
NengTyi	XPC5000	23.8	38.4		53.9	none	1	med	loud
Alpha	PAL8942	27.9	42.6		54.0	none	1	med	med
CPUMate	DIA-10500	22.8	39.3		55.5	none	1	med	easy
Zalman	CNPS6500-AlCu	23.1	40.3		57.4	none	1	low	easy
Glacialtech	Igloo 3300	22.4	40.5		58.8	silver	1	low	easy
Taisol	CEP426151A	24.3	43.7		59.7	none	1	med	easy
Intel	Socket 478	22.4	41.8		59.8	carbon	1	low	med
Arkua	838T-7G	23.3	42.0		60.0	none	1	med	easy
Dynatron	DC1207BMW	23.2	42.7		61.1	none	1	med	easy
Titan	TTC-MT3AB	22.8	41.5		61.2	none	2	loud	stiff
Dynatron	DC1206BM-S	22.4	43.2		62.0	none	1	med	med
AVC	117160	22.4	42.7		62.2	white pad	1	med	med
Eumax	DW-45	22.6	44.0		62.7	none	1	med	easy
Zalman	CNPS5700D-Cu	25.7	44.6		64.0	none	1	med	easy
Vantec	CCK-7025	27.0	45.4		64.1	none	1	med	med
JMC	400094	26.1	46.6		65.0	none	1	med	easy
Globalwin	VA476	28.7	49.5		68.0	grey	1	med	easy
Dynatron	DC1206BMV	23.1	45.1		68.2	none	1	low	easy
Vantec	GSN-7015	22.4	47.5		69.0	none	1	loud	stiff
Arkua	848X-6B	27.2	54.5		80.4	none	1	low	med
			50W		100W

It is obvious that the initial thermal results are pretty good for the JMC 400074 Skyjet 70 Pentium 4 heatsink. The large aluminum body and radial fin orientation work well to keep temperatures under control.

Rise Above Ambient Temp. (c)
Mfg.	Model	27mm large copper block		27mm large copper block
		50W		100W
Alpha	PAL8942	14.7		26.1
Zalman	CNPS7000-Cu	14.1		27.7
AVC	117140	15.2		27.8
JMC	401100	15.6		27.9
Coolermaster	IHC-H71	14.0		28.1
Arkua	8568	15.4		29.3
NengTyi	XPC5000	14.6		30.1
Taisol	CCP445172	17.5		30.7
JMC	400074	17.8		31.4
JMC	400124	17.1		32.6
CPUMate	DIA-10500	16.5		32.7
Thermal Integration (high)	TI-V7035TN	18.1		32.7
Zalman	CNPS6500-AlCu	17.2		34.3
Taisol	CEP426151A	19.4		35.4
Arkua	838T-7G	18.7		36.7
Glacialtech	Igloo 3300	18.1		37.1
Intel	Socket 478	19.4		37.4
Dynatron	DC1207BMW	19.5		37.9
Zalman	CNPS5700D-Cu	18.9		38.3
Vantec	CCK-7025	18.4		38.4
Titan	TTC-MT3AB	18.7		38.4
JMC	400094	20.5		38.9
Globalwin	VA476	20.8		39.3
Dynatron	DC1206BM-S	20.8		39.6
AVC	117160	20.3		39.8
Eumax	DW-45	21.4		40.1
Dynatron	DC1206BMV	22.0		45.1
Vantec	GSN-7105	25.1		46.6
Arkua	848X-6B	27.3		53.2
		50W		100W

For an extruded radial fin design I have to say the JMC 400074 Skyjet 70 performed better than our initial expectations lead on. Looking at the large aluminum heatsink and integrated 70mm fan which lacks all of the glossy marketing that so many other manufacturers employ, it is worth remembering that looks don't necessarily make the heatsink.

It would seem that good thermal design, good thermally conductive materials, good thermal interfaces and efficient airflow all work together on the JMC Skyjet 70 to provide an ideal set of thermal results.

The heatsink is not the most powerful Pentium 4 cooler on the reference list, nor is it the quietest, but it does offer a lightweight solution in a field of copper.

Weighing in at 315grams the all-aluminum JMC 400074 Pentium4 / Xeon heatsink uses a fairly simple design to achieve attractive thermal results. Given the airflow characteristics of our test environment it is hard to say just how well the heatsink would work in a drawn-air 3U server chassis, but given the radial fin design, orientation may be less critical than with more traditional extruded (boxy) heatsinks. The effects could be quite interesting to say the least. In any case, the test results of the JMC Skyjet 70 for use on a P4 really do speak for themselves.

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