Test Results of nMBP 15" Baseline Fan & Heat

Discussion in 'MacBook Pro' started by Ben8472, Jun 22, 2012.

  1. Ben8472 macrumors member

    Mar 22, 2008
    HI all!

    since i been trying to get real opinions on heat and fans on the new non-retina 15" MBP these days and got quite positive info on that i went to a nearby apple store today (not a real apple retail but a premium partner) and checked out the baseline 15" non-retina MBP.

    I started up 4 terminals with yes > /dev/null and let it run that for 10 minutes while i checked out the retina mbp (great screen, great formfactor, but imho not THAT much better considering the price)

    after 10 minutes at 4x 100% CPU load (checked through activity monitor) i couldn't hear the fans, the area above the keyboard that used to be ultra hot since the first unibody came out was easily touchable and you could comfortable rest a finger there. The underside of the MBP was very warm, not yet hot. Really pleasent difference to the older modells.

    + I couldn't hear the fans in the store (not many people were in the store, no music was playing, if the fans were a tiny bit running i probably wouldn't have been able to make it out, it was definitly very silent)
    + less heat (might be possible to sit on a couch with it and rest it on your legs while doing those 2-3 things in imovie or aperture without burning yourself)

    i was not allowed to install any fan monitoring program (store policy), so i can't tell at what RPM the fans were going that time.

    I will probably get one next week after considering all other options, I'll definitly won't go for a any pre-ivybridge computers after this tryout.

    Hope i could help anyone with this information.
  2. doh123 macrumors 65816

    Dec 28, 2009
    Apple changed around the sensors in the SMC. There are currently no Temp monitoring programs that work right for the CPU. iStat tries to report back a "CPU Heatsink" temp, but its always 40 to 50 C when idle, or when pressed hard for 20 minutes and the whole machine is very hot physically... so it cannot be correct, its much hotter than 50 in there.

    SMCFanControl does spin the fans up and down right though. I played with it (since its source code is available) to try to fix it to read CPU temps right, but I couldn't really get it. I finally found an SMC sensor I think is the CPU temp (or at least 1 core of it), but I think its reporting information back differently, so the normal formula to convert to Celsius is wrong, otherwise this thing was hitting 120º C.

    That said... the fan speeds.
    The left fan goes from 2000rpm to 5900 rpm, and the right fan foes from 2000rpm to 5500rpm. Why the 400 rpm max difference? I do not really know, but thats how the SMC is set.

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