aaron kulkis cmiqlkx91hotpopcom mike wrote thursday 14 february 2008 1554 per jessen wrote ok yesterday morning moved box outside hooked network power outdoor temperature 1c temperature rose 6 afternoon machine actually ran pretty stable throughout day one lockup needed hard reset havent able reproduce whilst running 4 x mprime temperatures seen sensors stabilised work system cpu temp3 outdoor 4 mprime 39 51 81 5 4 mprime 35 50 80 6 cooling interesting thing machine uses amd supplied cpu heatsink fan got additional fans heatsinks improve airheat flow improve cooling without looking watercooling first thing always get rid amd supplied fans ive used thermaltake type heatsinks fans know coolermaster thermaltake make pretty good equipment cpu cooling big case midtower full tower well system remains unstable automatically reboots maybe 1015mins running 4 x mprime ive already got rma think board going back could problem also remember fans bottom case blow inwards fans top case blow outwards quiescent state cfm cfm cfm cubic feetminute ft3minute essentially m3minute except dimensionless conversion factor 30 make clear cfm cfm cfm application thevenins current rule practically mathematical identity identity cfm cfm case would eventually explode conversely cfm cfm eventually case would completely evacuated mean 1 fan blowing rated 300 cfm 2 case fans psu fan blowing rated 300 cfm initially fans blow 600 cfm fans air pressure inside case dropped enough infan bring little 300 cfmand outfans blowing bit 300 cfm total little 100 cfm 13 rating additional inflow might provided leaks ventilation holes case event scenario air pressure case low means fans heat sinks used inside case cpu cooling etc operating environment less air density thing designed therefore cool well air inside case situation reversed 3 fans blowing 1 psu fan blowing still get quiescent state flowthrough slightly higher flow rate provided one fan initially infans blow 900 cfm outfan blows 300 cfmbut internal air pressure rises input fans flow rapidly drops 100 cfm outfan runs slightly rated capacity bit 300 cfm nowthe air within case increased pressure cpu fan blowing air molecules heat sinktherefore improving cooling ability heatsinkfan apparatus second example using case perforations air flow acceptable first example examples air flow performations happens due difference air pressure inside case vs outside case second example perforation airflow due higher air pressure thus higher air density inside case first example perforation air flow due vacuum condition inside case detrimental cooling cpu heat sink vacuum conditions within case always resolved increasing amount air forced case tue 05 aug 2008 040820 0500 opensuse unstable system culprit