MacBook Pro has 61W, MacBook Air 30W: why?

[NewUsername]

I noticed that a new MacBook Air has a 30W power adapter, but the MacBook Pro 13" has 61W. I found it interesting because both computers are very similar in many ways.

What does it mean? Does it mean the MacBook Pro can recharge faster (like an iPhone recharges faster with 12W or 18W instead of 5W)? Does it mean the MacBook Pro consumes more power when being used when connected to the charger? So would having MacBook Air instead of a MacBook Pro gives you a (very slightly) cheaper electricity bill?

Or in a more general way: why don't the MacBook Air and the MacBook Pro 13" come with the same power adapter?

I don't know much about the technical side, so I would be interested to know what more knowledgeable people have to say about this!

 

[nStyle]

61w will charge faster due to USB-C power delivery. But it will charge the MBA faster as well.

The charger just needs to be able to handle max power draw from laptop and also charge the battery so a 61w leaves more room. The difference in power draw was certainly more substantial pre-Retina for the Air so you would think that screen would at least bump it up into 45w territory since that's also a PD spec.

My guess is even 61w is overkill for the MBP despite a brighter screen and faster processor, but those are the reasons it's higher.

 

[thetman]

The power adapter wattage is the maximum output supplied to the laptop. The Intel CPUs Apple puts in its laptops have varying levels of max TDP, without looking up current generation, I would say maybe 5W to 25W on the highest MacBook Pro. Combined with out power consuming internal components like ThunderBolt chips a high end MacBook Pro might need most of that 60W from the adapter. A MacBook Air with a lower TDP CPU will need less and most likely Apple can produce 30W adapters cheaper.

As for cost, I pay ~12c/KWh. So if a MBP uses 30W more x 24hr x 365 days / 1000 to get KW x 0.12 = $31.5 difference. Thats over a whole year and if you are using the max power all day every day.

 

[jerryk]

MBPs have faster more power CPUs that have higher power requirements. Also, the display in the MBP is wider gamut and considerably brighter, so again has higher power requirements.

 

[FlyingDutch]

They are using totally different CPU and GPU, with different power consumption under load.