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macrumors bot
Original poster
Apr 12, 2001

Second-screen app Duet Display received a significant update today, introducing a new resolution option to support Apple's 12.9-inch iPad Pro and bringing significant performance improvements for both iPads and Macs that run the accompanying software.

For those unfamiliar with Duet Display, it's an app that is designed to turn the iPad or iPhone into a secondary display for a Mac. Duet Display was the first app to use a Lightning cable to allow an iPad or iPhone to interface with a Mac, thereby drastically cutting down on the lag that's typically present when an iOS device is used as a secondary display for a Mac over Wi-Fi.

Since its late 2014 launch, Duet Display has been updated several times to improve performance on a wide range of iPads and iPhones, but according to Duet Display developer Rahul Dewan, today's update brings "massive performance improvements." Improving performance was necessary to allow a Mac or PC to drive the high-resolution display of the iPad Pro while maintaining a lag-free connection, but the improvements also apply to all older iPads.

With the latest version of Duet Display, CPU usage has been reduced by over 80 percent on iPad and Mac or PC, thanks to a new algorithm that's more efficient and an intelligent refresh feature that's similar to the iPad Pro's own faster refresh technology, but on the software end. Extremely high CPU usage was one of our major complaints with Duet Display when it was first released and it's been a customer concern for some time, so this update should go a long way towards fixing one of the major pain points in the app.

Duet Display has proven to be a popular app with iPad owners as it gives the iPad the versatility to be used as a second display for a Mac. iPad Pro owners may find Duet Display to be especially useful given the large screen real estate of the device.

Duet Display can be downloaded from the App Store for $9.99 (reg. $15.99). [Direct Link]

Article Link: Duet Display Updated With iPad Pro Support, Major Performance Improvements


macrumors 65816
Aug 10, 2009
That's cool! So can I use an iPad Pro now as replacement for the MacBook retina screen?

I mean, rip off the screen and create a single hybrid tabled/laptop by combining the hardware?
Like an "Apple Surface Pro" :)


macrumors 68020
Mar 19, 2011
Now just give us that 2nd external screen!! Two old iPads that are begging to be used simultaneously as external monitors for my Retina Macbook!!!
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Sunday Ironfoot

macrumors regular
Apr 14, 2011
Does this thing still use a virtualised display driver, which hampers GPU performance?

From the FAQ:

When using Duet to preview video in Adobe Premiere the preview image turns black.

Sorry about that, this issue is occurring because Duet is not able to access the rendered preview image that Adobe Premiere is generating independently from the UI frame when GPU acceleration is turned on. As a workaround you can enable Software Only rendering by following these steps.


So it would appear that it does :-(


macrumors 6502a
Mar 28, 2013
** 40% Discount For A Limited Time! **

Im afraid there will be Duet Display 2


macrumors 68040
Apr 2, 2007
When I first used this on the Mac and iPad in my signature it was so laggy I found it unusable and refunded it with iTunes. I'll wait for reviews before I try it again.


macrumors member
Oct 5, 2015
So using is as a second screen would hinder performance for gaming on the main screen?
It won't. I use USB GPU to drive 3rd monitor on my Mac Mini, and the only thing that lags on two primary monitors driven by Thunderbolt ports is Mission Control. Games, iMovie and other accelerated apps work great as long as they're on primary monitors


macrumors 68040
Sep 19, 2007
Being as Lightning only supports USB2 speeds and iPad Air 2 and all latest Macs are AC gigabit wifi (which whilst not gigabit speeds, is still faster than USB2 in my testing) - you'd think someone would have come up with an even better wireless ad-hoc solution for the latest devices.


Apr 18, 2010
Would love to have audio pass through support (iPad Pro speakers are just that good).


macrumors 604
Mar 11, 2013
Duet is a huge productivity saver when I'm working at school with just my laptop and not my two external screens.


macrumors 6502
Oct 22, 2015
Is it only possible useing iPad as secondary screen in Duet ? what about the hole menu on OSX ? :)


macrumors 6502a
Jan 12, 2004
Actually, 2nd display is the most compelling reason I'd have for even considering an iPP. really curious to see how this pans out...


Jul 24, 2007
Troutdale, OR
I had an issue a few moths back where my Mac would not AirPlay to my Apple TV. After a few days I figured out duet breaks AirPlay support in OS X. Once I removed the OS X helper app, AirPlay worked again.

Until they fix this (which may not be possible) if you intend to AirPlay I would avoid this app.

Sunday Ironfoot

macrumors regular
Apr 14, 2011
So using is as a second screen would hinder performance for gaming on the main screen?

I've not used Duet Display, but I did use a similar utility called Air Display, and it absolutely did hinder GPU performance on the main display, which is why I stopped using it. I'd imagine this would be the same as it needs to use a virtualised display driver for your entire Mac while it's running, not just for the second screen. So the needing to disable OpenGL acceleration on various apps (such as Premier and PhotoShop) would apply even if you're running them on the main display.


macrumors G4
Sep 15, 2011
Vilano Beach, FL
I used Duet Display on the road a couple of times, I got so dual display dependent (I'm currently attending DDA ...), having a single display on a MBP really hampered me. It worked pretty well, even with a touch of latency and some CPU spikes on the host machine. Sounds like they've really dialed it in much better. I haven't used it in months, but I'll have to update and check it out again (hahaha, we only have an iPad Mini 2 now, so I guess my displays will be 24", 24" and 8" :D)


macrumors 6502a
Oct 21, 2015
I would say that I am impressed with Duet - now. I got it soon after it came out and it was terrible. Its had a lot of updates (both iOS and Mac) and now runs great.
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