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sbn

macrumors member
Original poster
Dec 5, 2015
39
13
While I'm waiting for my new 16" M1 Max MBP which replaces my current 2015 iMac 5K and 2018 15" MBP, I'm also looking for a new monitor solution and want something with built in USB-C power delivery.

However, most monitors on the market only delivers 65W over USB-C (except from a few HP Z series (100W) and a few Dell U-series (90W). The good old LG 5K 27" also only delivers 94W.

Can I run a 16" M1 Max reliably on 90 or even 65W without draining the battery? I know that the included magsafe 3 charger delivers 140W but with the increased energy efficiency in mind, I hope that the M1 Max will draw less power than my old 2018 intel machine? Is the 140 only for super fast charging, or does the beast really draw 140W continuously while working?

I'm going to compile software, browse with many open tabs, do photo editing and a little video editing.

With my 15" 2018 6 core i7 MBP I experienced that the battery lost some charge after a while, when the machine was fully loaded and connected to a 65W or less power source.

I don't care about fast charging, but I want to make sure that the laptop doesn't draw more power than my monitor can deliver over USB-C, when it's doing intensive tasks during the workday.

If I boot a 100% charged laptop, I expect it to still be at 100% charge after an hour of compiling, rendering etc.

So can anyone tell me how much peak power that a 100% charged M1 max 16” will draw?
 
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hovscorpion12

macrumors 68040
Sep 12, 2011
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As long as the monitor offers 60W of power, it can charge your Macbook. Won't charge as fast as the 140W, but it'll do the trick.
 

sbn

macrumors member
Original poster
Dec 5, 2015
39
13
Check out this article, it should be helpful:

To be honest, this article doesn't bring anything to the table at all. It doesn't answer my question about the power draw from the 16" M1 Max and it doesn't even mention the amount of power that the listed monitors can deliver over USB-C.
 
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sbn

macrumors member
Original poster
Dec 5, 2015
39
13
As long as the monitor offers 60W of power, it can charge your Macbook. Won't charge as fast as the 140W, but it'll do the trick.
I just clarified my question a bit.

With my 15" 2018 6 core i7 MBP I experienced that the battery lost some charge after a while, when the machine was fully loaded and connected to a 65W or less power source.

I don't care about fast charging, but I want to make sure that the laptop doesn't draw more power than my monitor can deliver over USB-C, when it's doing intensive tasks during the workday.

If I boot a 100% charged laptop, I expect it to still be at 100% charge after an hour of compiling, rendering etc.
 

vow

macrumors member
Jun 29, 2010
72
8
I don't have a monitor with PD but I do have my 16" m1 max hooked up to my 65W USB-C charger. It's been at 100% each time I've unplugged it, which is only twice so far since I got it on Thursday.

Just for testing, I have been building WebKit which keeps me at 100% CPU for most of the 15 minute build time. I am about 10 minutes in right now and see power consumption hitting 57W while battery is still at 100%.
 
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sbn

macrumors member
Original poster
Dec 5, 2015
39
13
I don't have a monitor with PD but I do have my 16" m1 max hooked up to my 65W USB-C charger. It's been at 100% each time I've unplugged it, which is only twice so far since I got it on Thursday.

Just for testing, I have been building WebKit which keeps me at 100% CPU for most of the 15 minute build time. I am about 10 minutes in right now and see power consumption hitting 57W while battery is still at 100%.
Thanks for useful feedback. Where do you see current consumption?
 

vow

macrumors member
Jun 29, 2010
72
8
Thanks for useful feedback. Where do you see current consumption?
Using istats to see everything right now. I saw in another thread that linked to the GitHub repo for the monitoring tool I’ve seen in MaxTech videos. Struggling to find it but I think that provides more info.
 

badsimian

macrumors 6502
Aug 23, 2015
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You would have to be continuously maxing the processor and GPU to end up draining the battery as well as the supplied power to the point where you ran out. The question is what percentage of say any one hour is it running at absolute full tilt? Your usage doesn’t suggest this would be anywhere near a high % so I’d think it should be fine.
 

fs454

macrumors 68000
Dec 7, 2007
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I'm using a 50w brick at my desk with my M1 Max 14", display at full brightness and continuous encoding work and I don't see the battery drain at all. Not sure exactly on the 16 but can't be too far off. My Intel i9 16" model would drain immediately on anything less than the factory 96w. My older 87w would have the battery draining at continuous high load.
 
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matthewadams

macrumors 6502
Dec 6, 2012
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I'm on 60W now and I don't see any drainage.
I was on 15W previously due to an incompatible old dock I had from my previous Macbook, and that did occasionally drain battery (when running some heavy CPU tasks like compiling massive amounts of code).

The artificial benchmarks can put power consumption all the way up to 100+W, but how realistic is that in prolonged day to day use anyway (https://www.anandtech.com/show/17024/apple-m1-max-performance-review/3).
 
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sbn

macrumors member
Original poster
Dec 5, 2015
39
13
You would have to be continuously maxing the processor and GPU to end up draining the battery as well as the supplied power to the point where you ran out. The question is what percentage of say any one hour is it running at absolute full tilt? Your usage doesn’t suggest this would be anywhere near a high % so I’d think it should be fine.
I don't expect it to drain the battery down to 0% but also I don't want to constantly drain and charge a few % of the battery every time I start an intensive task. The machine will be connected to power 95% of the time so I don't expect to put that many cycles on the battery per year.
 
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sbn

macrumors member
Original poster
Dec 5, 2015
39
13
I'm using a 50w brick at my desk with my M1 Max 14", display at full brightness and continuous encoding work and I don't see the battery drain at all. Not sure exactly on the 16 but can't be too far off. My Intel i9 16" model would drain immediately on anything less than the factory 96w. My older 87w would have the battery draining at continuous high load.
Thanks. So it seems like the machine itself does not use much power when running. Then I just wonder why they increased the wattage of the power bricks by almost 50% - but if fast charging is the only reason, I feel home safe :)
 

bryanck

macrumors member
Jan 18, 2008
58
26
Thanks. So it seems like the machine itself does not use much power when running. Then I just wonder why they increased the wattage of the power bricks by almost 50% - but if fast charging is the only reason, I feel home safe :)
Probably for fast charging. Even though max power draw is only ~60W, the battery is 100W/hrs so a smaller power supply would take a while to charge it.
 

azz3879

macrumors newbie
Sep 21, 2021
1
0
Hi @sbn I am in in a similar circumstance trying to find a monitor that will power of my 16” MBP M1 while under heavy load, without any draw on the battery. I was curious what the determination to your question was.

Thank you!
 

Zest28

macrumors 68030
Jul 11, 2022
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3,908
The 16" M1 Max MacBook Pro needs 100W charging atleast. Lower than that, it will use the battery under maximum load.
 
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