BEHIND THE SCENES IN COMPUTER COOLING Joo Matos

BEHIND THE SCENES IN COMPUTER COOLING João Matos Tiago Rosário Computing professional course

WHAT COOLS A COMPUTER PROCESSOR ? ? HEATSINK Heat exchanger used to transfer heat generated by a mechanical or an electronic device to the surroundings THERMAL PASTE FAN Thermally conductive compound, which is commonly used as an interface between heatsinks and processors Moves air across a heat sink to cool a particular component.

THE TEST • THREE COOLERS BENCHMARKED • THREE TERMAL PASTE COMPOUNDS TESTED • THREE MONITORING AND STRESSING TOOLS

THE COOLERS Intel Stock Cooler HP Server Cooler • Copper core • Aluminium Heatsink fins • 2700 rpm fan • 444 grams • Copper core • Copper heat pipes • Thin aluminium fins • High speed fan 5300 rpm • 351 grams • Copper core with heat pipes • Slower bigger fan • Tall • Very thin aluminium fins • 445 grams

THE THERMAL PASTES Phasac • thermal conductivity: • > 0. 925 W/m-K • Thermal Impedance: <0. 229 ºC/W • Low profile thermal paste Thermalright CFIII • Thermal Conductivity: >3. 5 W / m-K • Thermal Resistance: 0. 012°C / W • Medium profile thermal paste Gelid Extreme • Thermal conductivity: >8. 5 W/m. K • High profile thermal paste

THE SOFTWARE • INTELBURNTEST: INTELBURNTEST ENCOURAGE INTEL CORE 2 PROCESSORS TO ACHIEVE MAXIMUM PERFORMANCE BY PUSHING THEIR OWN LIMITS, EVEN GOING TO THE EXTREME OPERATING POINT. • HWMONITOR: HWMONITOR IS A HARDWARE MONITORING PROGRAM THAT READSPC SYSTEMS MAIN HEALTH SENSORS : VOLTAGES, TEMPERATURES, FAN SPEEDS. • CORE TEMP: CORETEMP IS A COMPACT, NO FUSS, SMALL FOOTPRINT, YET POWERFUL PROGRAM TO MONITOR PROCESSOR TEMPERATURE AND OTHER VITAL INFORMATION.

Tools Icons Core. Temp HWMonitor Intel. Burnr. Test

THE PROCESSOR Ø INTEL® CORE™ 2 DUO PROCESSOR E 8400 • NUMBER OF CORES: 2 • PROCESSOR BASE FREQUENCY: 3. 00 GHZ • TDP: 65 W • VID VOLTAGE RANGE: 0. 8500 V-1. 3625 V

THE RESULTS 3 rd Intel stock cooler 2 nd HP stock cooler 1 st HP server cooler • The arquitecture isn’t the best; • Too thick alluminium • Lower transfer rate between the copper core and the aluminium fins. • Cheaper to make • Great architecture • Heatpipes are a must have for transfering big amounts of heat from the processor • High speed fan • Noisy • Similar architecture as the HP stock cooler • Tall, so it can’t fit in all cases • Longer heatpipes improves cooling • As light as the Intel Stock cooler

THE BEST RESULT + 45 ºC

THE 2º BEST RESULT 55 ºC +

THE WORST RESULT 75 ºC +

THE CONCLUSIONS • • • COPPER IS GREAT AT EXTRACTING HEAT FROM THE PROCESSOR ALUMINIUM IS THE BEST CHOICE FOR DISSIPATING HEAT FROM COPPER CORES/HEAT PIPES THINNER ALUMINIUM FINS ARE BETTER AT DISSIPATING HEAT THE FASTENING SYSTEM CAN HAVE A HUGE IMPACT ON PERFORMANCE GOOD THERMAL PASTE CAN REDUCE IN 10 DEGREES THE PROCESSOR’S TEMP SO ITS A GOOD WAY TO REDUCE TEMPERATURE AT ECONOMICAL COSTS • SIZE AND WEIGHT DO NOT SAY EVERYTHING • CLOSED SYSTEMS MAKES COOLER'S ABILITY TO REMOVE HEAT FROM THE PROCESSOR MORE DIFFICULT • HIGHER FAN SPEED REMOVES HEAT FROM THE HEATSINK FASTER BUT CAN BECOME REALLY NOISY. • ROOM TEMPERATURE SETS THE AIR COOLING LIMIT