MCX4000™ Heatsink for Intel® Pentium® 4 Made in the USA       Patented DISCONTINUED   Features : The MCX4000™ heatsink is designed exclusively for Intel® Pentium® 4 processors. This product aims at offering the absolute ultimate performance in air cooling, and enabling users with the widest possible range of applications from ultra-quiet to extreme overclocking. The MCX4000™ heatsink can be used with either 70, 80, or 92mm fans. Construction: hybrid copper base, thin aluminum pin heatsink. The 3/8" thick copper base provides mass for superior energy absorption. The thin aluminum pins promote increased turbulence for more efficient heat dissipation compared to traditional fin extrusions. Patented Helicoid pin design (U.S. patent 6,469,898): pins are individually machined in an helicoid shape, to increase their surface area, and further enhance heat dissipation efficiency. Fan compatibility : effective 2-20-03 the MCX4000 is directly compatible with all the following fan classes: 70 mm fans 80 mm fans 92 mm fans, with the provided brackets. FANS SOLD SEPARATELY BY DISTRIBUTION CHANNELS 70MM 80MM 92MM Click on picture to enlarge Exceptional quality and attention to details: the heatsink base is lapped flat to 3/10 of 1/1000", and polished to near-mirror finish to promote optimum thermal conductivity. back to top Motherboard and CPU compatibility The MCX4000™ is compatible with all Intel® Pentium® 4 motherboards using the socket 478 form factor. TheMCX4000™ is NOT compatible with earlier Pentium® 4 socket 423 moterboards. back to top Retention Mechanism The retention mechanism is designed to prevent damage to the processor during installation or removal of the heatsink, or during shipping of a completely assembled computers. Each retention assembly (4 assemblies total) is composed of stainless steel standoff, secured to the motherboard by a locknut, a #6-32 Philips screw, and a spring. Installation of the standoffs requires removal of Intel®'s heatsink retention frame, and necessitates removal of the motherboard from the computer case. Crash tests were conducted by repeatedly dropping a case equipped with an MC462 heatsink, which uses the same retention mechanism, from the roof of a second story building. The heatsink remained securely attached to the processor, and the processor didn't suffer any damage.   back to top Performance/noise data vs. MCX478™ The MCX4000™ offers superior performance compared to the MCX478™ by virtue of it's increased size, mass & heat transfer area: 429 vs. 371 pins Comparative tests with a Pentium® 4 processor overclocked to 3 Ghz showed identical CPU temperature (±1°C) between an MCX4000™ equipped with a 36.8 CFM TMD® fan, versus an MCX478™ equipped with Delta's FFB0812SHE (68cfm) FAN. MCX4000™ C/W data (tested with a 36.8 CFM 70mm TMD® fan): 0.18 back to top Specifications Heatsink Base: CNC machined, C110 copper base, 3.14"W x 3.5"L x .375"H, flatness better than 0.001", micro surface finish 8 or better. 429 Helicoid Pins made of High Thermal Conductivity Aluminum Alloy, press fitted in the base. Overall heatsink dimensions 3.14"x3.5"x1.55" Weight: 21 oz (600g) Retention mechanism Motherboard fittings: 6-32 Female to Male 1/4" aluminum round standoffs with nylon washers and nylons nuts 4 compression springs  providing exact specified pressure per chip manufacturers. 70mm and 80mm fan mounting screws Back to top Suggested Retail Pricing Please consult your Swiftech distributor prior to ordering direct from us, or purchase the product factory direct here MODEL Factory bundled-FAN Mounting Hardware MSRP in US$ Motherboard heatsink & Fan MCX4000-B No Yes Yes $47 back to top