How many watts does the M1 MacBook really need?

[alexjholland]

My Caldigit Soho USB-C dock arrives tomorrow.

Like any bus-powered dock, it will eat a portion of the power supplied by Apple's charger - before sending the rest to the MacBook via Power Delivery.

Can I assume that Apple's 61W charger offers enough headroom to power the M1 MacBook Pro AND a few hard drives + webcam?

Otherwise, it seems that any dock owner has to buy a new, bigger, power supply.

 

[leman]

According to notebookcheck, average power consumption under load of the M1 MBP is around 30 watts, maximal power consumption is around 50 watts. This is for the entire laptop. Overall, I'd say that 61W charger is plenty for the laptop with some external devices connected.

 

[deeddawg]

That dock has two USB device ports if I remember correctly.

How exactly are you planning to attach "a few hard drives + webcam"?

Generally though, the power consumption will be pretty low unless you're pushing the system -- so you ought to be fine.

 

[jdb8167]

The 30W charger from the MacBook Air definitely doesn't have enough power to supply both USB-C and USB-A ports on my Caldigit SOHO dock. My M1 MacBook Air goes to sleep when using clamshell mode if I plug in an ethernet adapter and then a thumb drive. I guess if the charge falls off, the power circuit thinks the MBA isn't plugged in to the charger. There is a simple fix though without buying a larger charger (which I will do at some point). Just run sudo pmset -b disablesleep 1 from terminal.

 

[Argon_]

My Caldigit Soho USB-C dock arrives tomorrow.

Like any bus-powered dock, it will eat a portion of the power supplied by Apple's charger - before sending the rest to the MacBook via Power Delivery.

Can I assume that Apple's 61W charger offers enough headroom to power the M1 MacBook Pro AND a few hard drives + webcam?

Otherwise, it seems that any dock owner has to buy a new, bigger, power supply.

I often use a 30W charger with a two port Intel MBP. That chip uses a lot more power than an M1, so I think you'll be fine.

 

[alexjholland]

That dock has two USB device ports if I remember correctly.

How exactly are you planning to attach "a few hard drives + webcam"?

Generally though, the power consumption will be pretty low unless you're pushing the system -- so you ought to be fine.

I've got a 16-Port USB 3 hub that connects to the Soho's single 10GB USB-A port.

Pretty elegant, if it works.

 

[alexjholland]

Caldigit clearly state that the Soho dock will only pass 38W through from a 61W charger if you're running both USB-A and USB-C devices - link.

How does that sound?

Otherwise, any dock manufacturer should clearly state that you need an upgraded power supply to fully utilise the features of their dock.

 

[Argon_]

Caldigit clearly state that the Soho dock will only pass 38W through from a 61W charger if you're running both USB-A and USB-C devices - link.

How does that sound?

Otherwise, any dock manufacturer should clearly state that you need an upgraded power supply to fully utilise the features of their dock.

That'll still charge the machine under full load AFAIK, which makes sense given my use of a 30W brick.

The slower charging will also help with battery longevity.

 

[alexjholland]

That'll still charge the machine under full load AFAIK, which makes sense given my use of a 30W brick.

The slower charging will also help with battery longevity.

Nice. Losing even a few percentage points of performance would bother me, on principle.

 

[Argon_]

Nice. Losing even a few percentage points of performance would bother me, on principle.

You wouldn't lose any performance even with an undersized PSU. The machine would just dip into the battery under peak load. But I understand the sentiment.

On a related note, the slower cycling and better thermals of the Mx machines will mean robust battery longevity. The glued in Pro battery isn't nearly as damning as it was during the Intel era.

 

[deeddawg]

I've got a 16-Port USB 3 hub that connects to the Soho's single 10GB USB-A port.

Pretty elegant, if it works.

I'd be skeptical about the results you'll see from cascading hubs, but hopefully it works well for you.

 

[Krevnik]

I've got a 16-Port USB 3 hub that connects to the Soho's single 10GB USB-A port.

Pretty elegant, if it works.

That hub has it’s own power brick, yeah? If so, it won’t need to draw power from your power brick through the dock.

 

[Quackers]

It seems strange to me for Apple to supply a 31W charger for a machine that can use more than that.
My M1MBP only used about 4-5W when I was using it (but clearly doing nothing intensive).

 

[deeddawg]

It seems strange to me for Apple to supply a 31W charger for a machine that can use more than that.
My M1MBP only used about 4-5W when I was using it (but clearly doing nothing intensive).

Doesn't seem strange at all. The M1 Air apparently uses 30.3W under maximum load.

As Apple doesn't position it as a desktop replacement, there's no reason for them to include a larger/heavier higher wattage power adapter with millions of units just to accommodate the handful of folks attaching several devices without using a dock like a Caldigit TS3+ or OWC Thunderbolt dock which come with their own power supply.

The M1 MBP uses 47.5W under maximum load, and thus comes with the 61W supply.

 

[Quackers]

Doesn't seem strange at all. The M1 Air apparently uses 30.3W under maximum load.

As Apple doesn't position it as a desktop replacement, there's no reason for them to include a larger/heavier higher wattage power adapter with millions of units just to accommodate the handful of folks attaching several devices without using a dock like a Caldigit TS3+ or OWC Thunderbolt dock which come with their own power supply.

The M1 MBP uses 47.5W under maximum load, and thus comes with the 61W supply.

Exactly It doesn't ever use the 50W quoted in this thread.
If maximum draw is 30.3W then the 31W charger is plenty. No need for a bigger one.

 

[deeddawg]

Exactly It doesn't ever use the 50W quoted in this thread.
If maximum draw is 30.3W then the 31W charger is plenty. No need for a bigger one.

With that said, do remember that the M1 MBA will charge at up to ~41-42W initially per the cited notebookcheck review. That only effected a 17 minute reduction in the 2h 40min charge time with the 30 watt charger, so the actual utility of that ability is not (IMHO) going to make a substantive difference for most people.

 

[Wolff Weber]

I was able to charge my M1 MBA when idle with a 12W Apple Ipad charger, thought it didn’t charged during workload. But Samsung powerbank 1000 mAH didn’t work at all, even with MBA switched off.

 

[wytwolf]

I just did a cinebench R23 one pass test and the coconut battery app stated my M1 MBP was discharging at 21.72watts. So in most use cases you can get by with a 30 watt charger. My fan didn't kick in so you could add a few more watts and say about 23 with fan and maxed CPU. I guess the 40-50watt usage quoted above is when the CPU, GPU, fan and brightness were all @ 100%

I am now using an Anker 60W charger with 2 USBc ports. I can switch from 60W when one port is used to two 30W ports when both are used. It also includes world adapters and doesn't take up any extra space compared to the apple adapter. I think it's actually slightly smaller.

 

[jdb8167]

I just did a cinebench R23 one pass test and the coconut battery app stated my M1 MBP was discharging at 21.72watts. So in most use cases you can get by with a 30 watt charger. My fan didn't kick in so you could add a few more watts and say about 23 with fan and maxed CPU. I guess the 40-50watt usage quoted above is when the CPU, GPU, fan and brightness were all @ 100%

The Cinebench benchmark doesn’t use the GPU. The GPU will also use a lot of power so the 21W number isn’t representative of all high loads.

 

[Beau Slim]

Given that the guts of the Pro are essentially the same as the Air, I think they mostly included the 60W charger for faster charging.
Just a data point, and I don't *recommend* this charger, but I was feeling lazy and my m1 air was running low so I plugged it into a 23W Ikea Askstorm USB C charger and it charged just fine watching Netflix.

 

[deeddawg]

Given that the guts of the Pro are essentially the same as the Air, I think they mostly included the 60W charger for faster charging.
Just a data point, and I don't *recommend* this charger, but I was feeling lazy and my m1 air was running low so I plugged it into a 23W Ikea Askstorm USB C charger and it charged just fine watching Netflix.

See my post above.

47.5 watts measured maximum consumption for Pro vs 30.3 for Air.

yes you can use a lower rated charger, it’ll at worst just extend battery life if you’re consuming more watts than the charger supplies.

 

[AndrewNielsen]

In case anyone wonders in the future... I use my M1 13" MBP with the screen about half brightness for very light work.
• A power meter between the mains power and the charger said that it was using about 6.5 W.
• It lasted a bit over 12 hours until the battery went flat. 4.6 W if the battery is 58.2 Wh.
• Also, I used a Cygnet 27000 MAh, 99.9 Wh battery to power it. It needed about 90 Wh to charge it, measured as above. (I assume that the battery did not fully discharge because it still needed to produce 20V to charge the laptop.) It powered the laptop for 9 hours. Therefore, from the point of view of charging the battery, the MBP "used" 10 W.

The power meter was a Hypertec Power-Mate Lite. In Australia.

 

[SlCKB0Y]

According to notebookcheck, average power consumption under load of the M1 MBP is around 30 watts, maximal power consumption is around 50 watts. This is for the entire laptop. Overall, I'd say that 61W charger is plenty for the laptop with some external devices connected.

It's probably pretty important to note that is the power draw at the wall socket. The inefficiencies in the power supply will always mean that actual consumption is less. This can be a significant amount (as indicated by the heat given off by the power brick).

 

[jdb8167]

In case anyone wonders in the future... I use my M1 13" MBP with the screen about half brightness for very light work.
• A power meter between the mains power and the charger said that it was using about 6.5 W.
• It lasted a bit over 12 hours until the battery went flat. 4.6 W if the battery is 58.2 Wh.
• Also, I used a Cygnet 27000 MAh, 99.9 Wh battery to power it. It needed about 90 Wh to charge it, measured as above. (I assume that the battery did not fully discharge because it still needed to produce 20V to charge the laptop.) It powered the laptop for 9 hours. Therefore, from the point of view of charging the battery, the MBP "used" 10 W.

The power meter was a Hypertec Power-Mate Lite. In Australia.

According to Apple the M1 MacBook Air has a 49.9 Wh battery. I suspect that the MBA uses more power when plugged in than when on battery alone. When idling the M1 SoC sips power so the majority of the drain is from the display.

Edit: Didn’t notice the MBP instead of the Air.

 

[Hackaro]

Interested in discussion, in case I would recharge an M1 MBA on the go with a power solar system which output should I need from the solar panel on the USB-C port? Thanks!