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fazzio349

macrumors newbie
Original poster
Nov 30, 2018
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I was recently given a MacBook Air from my new employer to setup in my home office. It has 2 USB-C ports, and that's it. They gave me an adapter for a single monitor, but seeing as this monitor is small and I have an extra one lying around at home, I wanted to hook up 2 monitors. It looks like this isn't as easy to do as it sounds, especially with only 2 ports. Most docking stations I'm finding seem to only support one monitor, and I was hoping (although it doesn't seem promising) to not have to spend a ton of money on a computer setup for a computer that I don't actually own.

I had two ideas: Buy a single monitor support "docking station" that has a bunch of inputs and the ability to charge, and use the second USB-C port for the second monitor...or...find an "all in one" hub that supports 2 monitors leaving the other input free for charging or whatever. Does anyone have any good recommendations on the best way to do this and what products they use to accomplish this?
 

- rob -

macrumors 65816
Apr 18, 2012
1,030
705
Oakland, CA
I looked at this, see my other recent threads in this forum for some info. From what I can tell the graphics in the machine isn’t strong enough for dual 4K.

Something lower res might work.
 

saulinpa

macrumors 65816
Jun 15, 2008
1,270
783
Intel's specs for the UHD Graphics 617 that is in the 2018 MBAir state that it can drive 3 monitors at 4K with the caveat that you need to check with the vendor. The real issue is performance and what connectors. Performance depends on the individual. For dual monitors OP is correct that one of the two USB-C ports needs to use a dock or a monitor that provides power.

What we are waiting on is for someone to actually try dual 4k monitors and report back on their findings.
 

- rob -

macrumors 65816
Apr 18, 2012
1,030
705
Oakland, CA
Intel's specs for the UHD Graphics 617 that is in the 2018 MBAir state that it can drive 3 monitors at 4K with the caveat that you need to check with the vendor. The real issue is performance and what connectors. Performance depends on the individual. For dual monitors OP is correct that one of the two USB-C ports needs to use a dock or a monitor that provides power.

What we are waiting on is for someone to actually try dual 4k monitors and report back on their findings.
I admit I’m surprised to hear 3 monitors at 4K is possible on the new MBA. Would you please link to the spec pages suggesting this is the case?
 

robvas

macrumors 68040
Mar 29, 2009
3,240
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USA
Just use 1 USB-C port per monitor. You need a very expensive dock + an adapter to do two displays on one Thunderbolt port

Why is wrong with buying a pair of Apple’s USB-C Digital AV Multiport Adapter ?
 

0092762

Cancelled
May 29, 2005
273
316
Intel's specs for the UHD Graphics 617 that is in the 2018 MBAir state that it can drive 3 monitors at 4K with the caveat that you need to check with the vendor. The real issue is performance and what connectors. Performance depends on the individual. For dual monitors OP is correct that one of the two USB-C ports needs to use a dock or a monitor that provides power.

What we are waiting on is for someone to actually try dual 4k monitors and report back on their findings.

I am using dual 4K monitors (LG 27UD58) at 60hz each with my 2018 air. I use the Cable Matters thunderbolt 3 to dual hdmi 2.0 adapter ($89): https://www.amazon.com/Cable-Matters-Thunderbolt-Supporting-Compatible/dp/B01DYFI0AY/

I use a standard 20-25$ adapter that has 3 usb-a ports plus a usb-c port on my other port so I can plug stuff in and still have power.

Speed is fine for my intended use which not gaming. The fan does seem to kick in a bit more working like this however, also probably due to me using the scaled mode with 2560x1440 equivalent.
 
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- rob -

macrumors 65816
Apr 18, 2012
1,030
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Oakland, CA
I am using dual 4K monitors (LG 27UD58) at 60hz each with my 2018 air. I use the Cable Matters thunderbolt 3 to dual hdmi 2.0 adapter ($89): https://www.amazon.com/Cable-Matters-Thunderbolt-Supporting-Compatible/dp/B01DYFI0AY/

I use a standard 20-25$ adapter that has 3 usb-a ports plus a usb-c port on my other port so I can plug stuff in and still have power.

Speed is fine for my intended use which not gaming. The fan does seem to kick in a bit more working like this however, also probably due to me using the scaled mode with 2560x1440 equivalent.
Thanks for this. Are you able to get other USB ports with a second dongle on the other usb-c? If so what are you using there?
 

Airboy1466

macrumors 6502
Feb 23, 2015
326
31
Don’t not run a dual set up off of this air you will hate yourself it’s going to bottle neck like crazy it’s a core m processor Apple just threw in a fan for fun.
 

- rob -

macrumors 65816
Apr 18, 2012
1,030
705
Oakland, CA
Yes, I use a usb-c dongle on the other port that has a usb-c power input so I can have ports and power.
https://www.amazon.com/Adapter-Ethernet-Reader-Compatible-MacBook/dp/B07GGWT8LV/
I don't use the HDMI port here, it's for USB and Ethernet.
Thanks. Can you further characterize the amount of fan you’re getting while dueled up?

Also, in my tests, I sometimes had substantial cpu load running video through a dongle. It may have just needed a restart, but are you seeing the cpu do lots of graphics work in general use?
 

Airboy1466

macrumors 6502
Feb 23, 2015
326
31
Thanks. Can you further characterize the amount of fan you’re getting while dueled up?

Also, in my tests, I sometimes had substantial cpu load running video through a dongle. It may have just needed a restart, but are you seeing the cpu do lots of graphics work in general use?
The CPU cannot handle it you are gonna kill the machine before it’s time
 

Airboy1466

macrumors 6502
Feb 23, 2015
326
31
Did you get this info from Fox news or the New York Post?

lol no I'm just being a bum I just hate apple for putting a core m in it and the guy use it on dual 4k monitors and is on here a few hours latter ranting that it won't run efficiently.
 

saulinpa

macrumors 65816
Jun 15, 2008
1,270
783
I don't have one but specs say the 2018 MBA has an i5-8210Y processor. A mobile processor but not a core m. It's close but is a step up.

The Air is not meant to be a powerhouse but you are always going to find someone that will push it to its limits. Similar thing going on in the other section with the mini. Some are complaining that the mini can't handle dual 4K to their satisfaction but others say it works great.
 

0092762

Cancelled
May 29, 2005
273
316
Thanks. Can you further characterize the amount of fan you’re getting while dueled up?

Also, in my tests, I sometimes had substantial cpu load running video through a dongle. It may have just needed a restart, but are you seeing the cpu do lots of graphics work in general use?

The fan ramp up is if you use scaling, I scale for 2560x1440 so it actually renders at 5120x2880 and downscales to 4k each on dual monitors. As you can see, that is quite a heavy load for a Macbook Air. If you don't use scaling, it works fine. With scaling you literally cannot run 4k youtube video (use chrome as safari doesn't support it) smoothly. This is due to the way OSX handles scaling.

Also, you're not going to "kill the machine" by running that, that's just bs.
 
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- rob -

macrumors 65816
Apr 18, 2012
1,030
705
Oakland, CA
The fan ramp up is if you use scaling, I scale for 2560x1440 so it actually renders at 5120x2880 and downscales to 4k each on dual monitors. As you can see, that is quite a heavy load for a Macbook Air. If you don't use scaling, it works fine. With scaling you literally cannot run 4k youtube video (use chrome as safari doesn't support it) smoothly. This is due to the way OSX handles scaling.

Also, you're not going to "kill the machine" by running that, that's just bs.
Okay, yes this is what I would do as well. It is what you’d need to do in order to get 4k on each 4K monitor—which is what I’m after.

This is what I expected actually, it dual 4K would be heavy load or not even run some things in a reasonable way.

I wouldn’t be worried about burning out the machine, but I do wonder about the simple practical use of it.

I sort of wonder if it would be better to just get an upgraded Mac mini to run dual 4ks for and abandon trying to make my portable a dock able workstation.

For now it is working well with the single 4K, but there are times when it would be nice to have a high power dual 4K setup.
 
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