Passive vs. Active CPU cooling with Thermalright Coolers

Test Hardware Configuration

To simulate real-world conditions, all testing was performed on an Intel P4 Extreme Edition LGA775 955 dual core CPU inside a closed mid-tower case.  The following equipment was used.

 

Test Rig Configuration

 

• SilverStone SST-TJ05 mid-tower case^1,2
• Asus P5N32-SLI Deluxe motherboard
• Pentium 4 Extreme Edition dual core 955 @ 3.46 GHz
• (2) Corsair CM2X512-8000UL DDR2
• nVIDIA 7800 GTX 512 MB video card
• Western Digital WD1200JD S-ATA HDD
• SilverStone Zeus ST75ZF 750W PSU
• Windows XP Pro with SP2
• nVIDIA 91.31 nForce driver

¹Two 120mm case cooling fans, one in front, one in the back

²Rear stamped case fan grill removed and replaced with wire grill

 

 

Heatsinks and Fans

 

The Thermlaright HR-01 passive heatsink was tested in passive mode (no fan or fan duct) and pseudo-passive mode using the Thermalright 120mm Fan Duct that comes with the HR-01.  When using the fan duct, air is pulled thru the HR-01 by the rear 120mm SilverStone case fan (1,900 rpm).

 

 

HR-01 in Passive Cooling Mode

 

 

 

 

HR-01 in Psuedo-Passive Cooling Mode using Thermalright 120mm Fan Duct

 

 

An Antec 120mm TriCool fan was used with the XP-120 and Ultra-120 heatsinks at three different speeds (2,000 — 1,600 — 1,200 rpm).  The stock SilverStone case fans were used during all the tests.

 

 

XP-120 in Active Cooling Mode

 

 

 

 

Ultra-120 in Active Cooling Mode

 

 

Test Instruments

 

To facilitate taking more accurate CPU temperature measurements, a very small Omega thermocouple was attached to the side of the P4-955 IHS with Arctic Alumina thermal epoxy.  Two Barnant Model 115 digital thermometers (accuracy +/- 0.4º C) were used to measure CPU/IHS and internal case air temperatures.  A FLUKE 52 II digital thermometer was used to measure the ambient room air temperature.

 

Software Utilities

 

• Lavalys Everest Ultimate Edition 2006 (hardware monitoring)
• Asus PC Probe II (hardware monitoring)
• CPUBurn (load the CPU)

Note: Four instances of CPUBurn were executed at the same time (two to load both physical cores, and two to load the two virtual HyperThreading cores), which resulted in 100% CPU usage.

 

 (click to enlarge images)