Lightingguy wrote...quote...
I respectfully submit that, short of the quantifyable heat dissipation potential of the tested devices, in-situ testing of HSF is a useful but innacurate benchmark due to the (noted) variations present in hardware monitoring devices on MBs. In addition, the method of mounting, thermal pad/paste/grease application, and other factors may, in fact, have a greater bearing on just how these units operate within systems. That's why some people have great results with Super Coolers, and some curse their Hedgehogs. end quote....
We also respectfullly and heartily agree. And let us demonstrate the validity of this point of view by considering similar attempts to test cpu to hs interface materials with in-situ testing. We are all aware of "review sites" contesting the effectiveness of silver grease and esp the latest product Arctic Silver over zinc oxide grease, using in-situ testing with above mentioned inaccurate mobo hardware monitoring devices and procedures, and absolutely no idea of cpu power dissipation. This is the height of foolishness and "self interest of review sites", when we know from credible published material properties that silver greases are typically ~11.5X more thermally conductive than the Radio Shack Zn0 grease. Point...why in heavens name does anyone need to conduct these inaccurate in-situ tests. One can more accurately "calculate" the reduction in die temp for any estimated or chip mfr's max spec power dissipation. Review sites would be better advised to publish appropriate tables based on these data.
Problem with "heatsinks" is that mfrs' tests of thermal res, C/W, are not necessarily available, nor necessarily standardized, leaving the door ajar just enough for third party intervention, however inaccurate. Maybe someone should collect and publish whatever mfrs' test data and procedures may be available.
John C.
PS:-A few years ago, Aavid, a well respected long term player in the electronic thermal solutions arena, designed a very professional experiment/apparatus to test the "Thermal Performance of Interface Materials in Electronic Packaging Applications"...happens to be the title of the paper authored by Messrs Early, Lee, and Pellilo, selected from following page.
http://www.aavidthermalloy.com/atp/techpaper/techpaper.html
Unlike the many "young Tom Edisons" who rely on one improperly located thermistor by mobo mfrs, the Aavid engineers placed interface materials between extemely highly polished surfaces of 1 sq in aluminum rods, completely insulated, metered heat flux, and accurate temp measurement techniques to measure the temp drop across those polished surfaces which had as closely as possible no temp differences along either surface... ie isothermal surface temps. They also controlled and measured contact pressure. Worth a read to learn what it takes to design an accurate experiment.