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Corncab44

macrumors regular
Jun 22, 2020
228
61
Just got my i9 MacBook Pro (standard config - 1TB, 16GB). MAN is this thing noisy connected to the LG 27" 5K monitor. Forget using it with the laptop display open - it's a hair dryer. And even in clamshell mode just watching some MLS on Fox Sports, fan is rapidly approaching 4,000 rpm, with the Radeon around 17W usage, which is insane.

What is going on here? Even my 2014 27" iMac, which this replaces - had no issue with just watching a streaming video without burning up.

Hah yea, forget watching video on a monitor. I'm on a 4K dell and any sort of YouTube video ramps up the fans. You can stop turbo boost but it only helps so much since the problem is from the dGPU. You going to return it? I guess with headphones it's manageable but it's dumb as hell since Apple could fix this if they wanted to... just let us use the iGPU!!!
 

WilliamG

macrumors G3
Mar 29, 2008
9,924
3,800
Seattle
Hah yea, forget watching video on a monitor. I'm on a 4K dell and any sort of YouTube video ramps up the fans. You can stop turbo boost but it only helps so much since the problem is from the dGPU. You going to return it? I guess with headphones it's manageable but it's dumb as hell since Apple could fix this if they wanted to... just let us use the iGPU!!!

No not going to return it. But it really is a joke the thermal performance. The worst I’ve seen on an Apple laptop.
 

tutubibi

macrumors 6502a
Sep 18, 2003
571
72
localhost
Not sure if you are using docking stations to connect monitors but in my case if I connect via USB-C docking station (requires DisplayPort drivers), my MacBook Pro gets extremely hot. When connected via CalDigit Thunderbolt docking station, way less heat and noise for the same workload.
 

sco

macrumors regular
Apr 11, 2013
117
88
Brisbane, Australia
My 5600M model reports x8.

The processor has 16 lanes in total for direct connection:
https://ark.intel.com/content/www/u...9880h-processor-16m-cache-up-to-4-80-ghz.html

The difference between x8 and x16 in practical terms is small: e.g.

Using all 16 lanes just for dGPU would mean all other PCIe devices connect via the platform controller hub which then introduces latency.

Not sure how accurate this is.. assuming it is.. worth a read also for context:
 
Last edited:

apr

macrumors newbie
Jul 14, 2020
25
21
Is this a silent driver update from Apple? (16pci lane to 8pci lane)
Is this possible without going to app store and installing an update?!

I've experienced the same issues as others in this thread: high fan noise and temp with external monitor. This is for the last two weeks (my machine is only two weeks old). I've tried everything, turbo boost switcher etc., nothing helped. The avarage fan speed was 3500-3600 with turbo boost disabled. With turbo boost enabled I saw fan speed over 4000, and temp spikes over 90 C. Clamshell mode helped a little.

But from today morning the issue seems to gone for me: max fan speed was 3200, but 95% time stays between 2500-2800. This rpm is barely audible and the same as in my old macbook pro 15 (model year 2017) with the same setup.
Temp is 60 C. RPM and temp values from turbo boost switcher, and turbo boost was not disabled(!)


My workflow for today: open lid, running outlook on the macbook pro's screen, listening music, safari surfing, working in parallel vm (scaled resolution), main screen is LG 5K first generation (which has 85w power supply) connected with the original tb3 cable (this is the only power supply for the mac), and connected a belkin gigabit ethernet adapter, using usb dongles on the LG 5K back.

My config: macbook pro 16, 64Gb ram, 2TB ssd, 5500M 4Gb
 
Last edited:

WilliamG

macrumors G3
Mar 29, 2008
9,924
3,800
Seattle
Not sure if you are using docking stations to connect monitors but in my case if I connect via USB-C docking station (requires DisplayPort drivers), my MacBook Pro gets extremely hot. When connected via CalDigit Thunderbolt docking station, way less heat and noise for the same workload.

I’m using the Caldigit TS3 Plus. Still super noisy.
 

richie.cl

macrumors newbie
Feb 15, 2016
12
1
anyone noticed improvements with apple changing from x16 to x8?

How do I check that I got the “silent update”?
 

ateslik

macrumors 6502
Oct 18, 2008
401
523
anyone noticed improvements with apple changing from x16 to x8?

How do I check that I got the “silent update”?

My 5600M reports x8, and has since I got the machine on 7/9. I know this because I took screenshots of that screen (posted here around page 100). I don't think there was a "silent update", I think this was part of the 10.15.5 Supplemental Update. But I can't say with certainty.
 

Corncab44

macrumors regular
Jun 22, 2020
228
61
My 5500m reports 8x. Not sure what it was before. But in any case my 16 inch is as hot as ever, fans blasting, drawing 20 watts when connected to a monitor and screen open. Not sure this helped anything if it was changed.
 

ateslik

macrumors 6502
Oct 18, 2008
401
523
this post clearly shows the x16 PCIe channels, but later posts in May show x8:

 
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Reactions: dooyou

Corncab44

macrumors regular
Jun 22, 2020
228
61
Seems like this channel thing is a red herring, even if it was intended to fix something. Clearly our laptops are still blazing hot when plugged into external monitors.
 

MrGunnyPT

macrumors 65816
Mar 23, 2017
1,313
804
1594744271436.png
 

dooyou

macrumors 6502
Jun 5, 2007
368
269
Munich
Damn Apple, this shouln’t be that difficult to fix

What makes you think it shouldn't be hard to fix? If it were, there'd be a fix already. The problem with the cracking speakers had been dealt with quickly. There must be a reason for that. Maybe its not so easy to fix or maybe there will be never a fix for that.
 

magbarn

macrumors 68030
Oct 25, 2008
2,957
2,253
Hah yea, forget watching video on a monitor. I'm on a 4K dell and any sort of YouTube video ramps up the fans. You can stop turbo boost but it only helps so much since the problem is from the dGPU. You going to return it? I guess with headphones it's manageable but it's dumb as hell since Apple could fix this if they wanted to... just let us use the iGPU!!!
I don't know if you're aware but using the iGPU when connected to an external monitor will require a logic board redesign as only the dGPU is hardwired to external monitor connections. It's Apple's choice of design which is the opposite of Windows laptops which the iGPU is the one hardwired and the dGPU routes through the iGPU when connected to external
 
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