Arch Linux

madalu

Member

Registered: 2009-05-05

Posts: 217

[SOLVED] MacBook Wireless card too hot in Linux?

I've got Arch up and running smoothly on a MacBook (4,1).

When I run sensors, it spits out the output attached below. Perhaps my googling skills are not so good, but I haven't been able to find a clear guide detailing which monitor each temp value represents. I obviously know what the first two values are (Core 0 and Core 1). But I'm a bit confused about a few of the other values. The "temp6" monitor seems ineffective -- it stays constantly at 65. The "temp7" monitor, on the other hand,  shoots up very quickly after boot to the mid 70s and will keep rising into the 80s unless I rev up the fan.

I'm thinking that this is perhaps wireless chipset and am concerned that the value is usually considerably higher when running Arch than the "Wireless Module" reading when running OSX (usually stays in low 60s with heavy network activity).

Any tips from MacBook users would be greatly appreciated. Thanks.

coretemp-isa-0000
Adapter: ISA adapter
Core 0:      +34.0°C  (high = +100.0°C, crit = +100.0°C) 

coretemp-isa-0001
Adapter: ISA adapter
Core 1:      +34.0°C  (high = +100.0°C, crit = +100.0°C) 

applesmc-isa-0300
Adapter: ISA adapter
Exhaust  :  3997 RPM  (min = 1800 RPM)
temp1:       +32.0°C                                   
temp2:       +46.0°C                                   
temp3:       +44.8°C                                   
temp4:       +51.5°C                                   
temp5:       +45.0°C                                   
temp6:       +65.0°C                                   
temp7:       +70.5°C                                   
temp8:       +45.2°C                                   
temp9:       +45.0°C                                   
temp10:      +44.8°C

----

Edit reason: solution was premature. Resulted in degraded network activity.

Last edited by madalu (2009-06-18 01:41:18)

madalu

Member

Registered: 2009-05-05

Posts: 217

Re: [SOLVED] MacBook Wireless card too hot in Linux?

I answered my questions with a bit more googling and experimentation:

1) I found the following values for the temperature sensors on the
MacBook on the mactel-linux thread (http://www.mail-archive.com/mactel-linu … 00516.html).

chip "applesmc-isa-0300"
    label "temp1" "Ambient"
    label "temp2" "Enclosure Bottom"
    label "temp3" "CPU A"
    label "temp4" "unknown TC0P"
    label "temp5" "GPU Heatsink"
    label "temp6" "GPU"
    label "temp7" "unknown TG0T"
    label "temp8" "Heatsink A"
    label "temp9" "Heatsink B"
    label "temp10" "Memory Controller"
    label "temp11" "unknown Ts0P"
    label "temp12" "unknown Ts1P"
    label "fan1" "Left Fan"
    label "fan2" "Right Fan"

chip "coretemp-isa-0000"
   label temp1 "Core0"

chip "coretemp-isa-0001"
   label temp1 "Core1"

2) I confirmed through experimentation that "temp7" is almost certainly the wireless chipset (Broadcom 4238). By rebooting back and forth between systems, I found that the values usually corresponded. (The temperature dropped a bit while the wireless card was inactive during reboot, but quickly went back to the previous level once the wireless card was turned on.)

3) I confirmed that the temperature of the Wireless Card rose much more quickly and steeply on Arch than in OS X. Even without much network activity, the temperature shot up to the mid 70s Celsius. (I'm using ndiswrapper rather than broadcom-wl.)

I only reached this temperature in Mac OS when doing network intensive things like watching streaming movies or downloading MacTeX (all 1.2 gigabytes of it)!

4) I solved my problem by turning on wireless power management via iwconfig (iwconfig wlan0 power on). I'm not yet clear on all the different power management settings here, but this keeps my wireless card temp readings in the same range as MacOS. My surmise is that without this setting the wireless card was running at full power all the time in Arch (even when inactive) and thus becoming rather hot.

5) I'm wondering whether wireless card settings are one of the reasons that people often complain that MacBooks run hotter in Linux than MacOS. Mine would very quickly reach 75 degrees and the corresponding area of the MacBook became very hot to the touch. With power management turned on, things feel a bit cooler. My wireless card is currently running at 60 degrees Celsius rather than the blazing temperatures it previously maxed out at.

madalu

Member

Registered: 2009-05-05

Posts: 217

Re: [SOLVED] MacBook Wireless card too hot in Linux?

My mistake: Setting power management to on in iwconfig leads to heavy packet loss and lots of latency. I can live with the heat so long as I turn on the fan.

madalu

Member

Registered: 2009-05-05

Posts: 217

Re: [SOLVED] MacBook Wireless card too hot in Linux?

O.K. I'll provide one more update in this ongoing monologue:

It seems that the combination of ndiswrapper + broadcom driver (windows) + iwconfig allows only one power saving setting. None of the power options I enter with iwconfig work (period, timeout, min, max, etc. -- see man iwconfig for more details). The only setting that works is "iwconfig wlan0 power on", which does a nice job of keeping the card in a reasonable temperature range but delivers a huge blow to network performance (slow pings and packet loss).

Unfortunately, I haven't been able to get the new broadcom-wl driver to work to see if the temperature is any better. I'll keep trying...

madalu

Member

Registered: 2009-05-05

Posts: 217

Re: [SOLVED] MacBook Wireless card too hot in Linux?

Well, after seeing the wireless card reach 74 degrees when running OS
X, I'm no longer worried about this issue. It seems the wireless card
gets quite hot when the battery is recharging. Marking issue
solved....

rvega

Member

From: Colombia

Registered: 2011-12-20

Posts: 25

Re: [SOLVED] MacBook Wireless card too hot in Linux?

Thanks for posting this. Did you ever get this fixed? eg, wireless card running normally with cooler temps? does your lapto still feels too hot to the touch?