Information not expressly stated in the Final Rise above Ambient Temperature Test Results List concerns the pre-applied thermal pad (we remove this for testing any way), the number of fans on each heatsink, general fan noise and clip force observations, and ambient temperature measurements. As always, FrostyTech's Synthetic Temperature Test results for the Socket 478 Intel Pentium 4 platform are grouped according to the results for the 100W test die.

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

( Socket 478 - Pentium4 ) Rise Above Ambient Temp. (c)
Mfg.	Model	27mm large copper block		27mm large copper block
		50W		100W
Cooljag (high)	CJC66IC-A	10.4		21.3
Gigabyte (high)	PCU31-VH	12.5		22.3
Coolermaster (high)	Hyper6 KHCV81U1	12.4		23.4
Asus	Crux P4 XB7N (H)	13.9		24.4
Zalman	CNPS7000A-Cu	12.4		24.9
Alpha	S-PAL8952	12.7		25.4
AVC	Z7U7408001	12.9		25.8
Alpha	PAL8942	14.7		26.1
Gigabyte (high)	3DCooler-pro	15.6		26.6
Zalman	CNPS7000-Cu	14.1		27.7
AVC	117140	15.2		27.8
JMC Products	401100	15.6		27.9
Coolermaster (high)	Jet4	12.6		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
TTIC	NPH-101	13.4		31.2
Thermal Integration	TI-RV108N	15.9		31.7
Vantec	VP4-7245	18.0		31.7
Thermal Integration (high)	TI-V7035TN	18.1		32.7
Verax	Polargate AL S	17.0		32.9
AVC	Z7H2403012	15.2		33.4
Cooljag	JVC661A	17.3		33.5
TS Heatronics (6" fan dist)	NCU-1000	15.6		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	838T-7G	18.7		36.7
Intel	Socket 478	19.4		37.4
Zalman	CNPS5700D-Cu	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
Asus	Crux P4 XB7N (L)	19.8		39.5
AVC	117160	20.3		39.8
Evercool	CUW8-715	21.8		40.8
Arctic Cooling	SuperSilent4 Pro	21.7		43.0
Verax	P16Cu	22.0		45.1
Verax (high)	P17CuX	27.8		47.6
Verax	P16	27.4		54.0
Dynatron	DC1U-B02	32.9		67.4
		50W		100W

The drive to create nearly silent active heatsinks presents several challenges to the consumer and thermal engineer alike. For starters, thermally controlled fans are often slave to internal ambient temperatures, rather than accurate responses to the processor's temperature. This keeps noise low, but doesn't always ensure that low CPU temperatures are maintained.

In our tests, it's clear that the Asus Crux P4 XB7N, while running in its most silent mode, is not a formidable cooler for the Pentium4 platform. This is simply because airflow and surface area are too low.

While the Crux P4 does produce satisfactory thermal results, and is nearly silent in this mode, it is nothing an overclocker would choose... at first glance. The tables turn, and turn sharply when the Delta fan aboard the Asus Crux P4 XB7N rises to full RPM. With the Delta fan spinning away at 5400RPM, the Asus Crux P4 becomes a high performance heatsink, perfect for overclocking!

Its full copper construction, and unique exhaust pattern give it the thermal efficiency to rank near the top of our list of reference heatsinks. Ultimately, this makes the Asus Crux P4 an excellent high performance Pentium 4 heatsink, but only a satisfactory low-noise cooler. Better low noise cooling can be had by choosing a heatsink specifically designed for that task, like the Zalman CNPS7000B-Cu.The Asus Crux P4 XB7N heatsink is an excellent choice for performance cooling at noise levels of about 53 dBA, and offers some satisfactory low noise cooling on the side.

Related Articles:

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

1. Coolermaster Hyper6 KHCV81U1 Review
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. Alpha Novatech S-PAL8952 Pentium4 Heatsink Review
8. Verax P17CuX Ultra Quiet Heatsink Review