4K (3840 by 2160) with the new rMB
- Thread starter iRun26.2
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Yes. But will the core M support 1920x1200 scaled using a 3rd party app without active cooling. That's the question.
iRun26.2
macrumors 68020
But Apple's spec sheet itself specifies 3840x2160. So, then, it must be 30Hz? Is that really bad at 30Hz?
I am far from expert but would using this work
https://store.google.com/product/usb_type_c_to_displayport_cable
It claims 4k at 60
https://store.google.com/product/usb_type_c_to_displayport_cable
It claims 4k at 60
iRun26.2
macrumors 68020
Now that would really get the "rMB haters" going!:
You could buy a fan/cooler accessory to cool your new rMB so that it could work at 4K at 60Hz like rMBP machines.
Running at 1920x1200 upscaled to 2304x1440 would work I suppose (but on a 12" screen, I don't really think it would be much usable).
- It's really quite interesting how many uninformed people on these forums make this claim. It's nonsense.
DisplayPort 1.2 is natively supported through the connection, providing more than enough bandwidth for 4K.
Also, the USB 3.1 on the rMB is Gen 1, so it actually only supports 5 Gbps.
Cool username, by the way...
So are you saying it is possible with a display port dongle
iRun26.2
macrumors 68020
Does DisplayPort 1.2 specify whether 30Hz and 60Hz are both supported?
ctyrider
macrumors 65816
DP 1.2 supports 3840 x 2160 at 60Hz. Any lower refresh rates are also supported.
iRun26.2
macrumors 68020
I would think that it would be rather challenging for a 5W part to support 4K video at 60Hz.
ctyrider
macrumors 65816
Yes it would be. Display Port bandwidth isn't the only factor in system's ability to support 4K at 60Hz.
iRun26.2
macrumors 68020
I'm kind of excited about this. I only need to convince my boss at work to buy a 4K monitor for me. I pay for my own computer so I think I could get him yo pay for that if it really works.
- I am saying that the connection itself supports it. Whether the computer as a whole will be able to handle 4K at 60 Hz is another matter. I doubt it will due to a lack of sufficient cooling of the Core M processor.
iRun26.2
macrumors 68020
I am uncertain what you meant by 'coding' of the Core M processor. Are you saying that it is a software thing?
MyopicPaideia
macrumors 68020
He wrote Cooling, not Coding.
I am pretty sure it will be 30Hz. This will be perfectly fine for what the machine is intended for, i.e. Office work and light load photo and movie editing (as in iMovie and the Photos app). Would be very frustrating for high end 3D games though. But then again, the Macbook is not going to be running into this point as the bottleneck anyway. The GPU will be the limiting factor here.
DP 1.2 native through the connection, like he said, means that the port itself supports full DP 1.2 capabilities, but I am pretty sure 60Hz won't be supported...at least not until the Skylake Core M processor.
However, if you run the machine in mirroring mode, and not as a second display, and shut the lid, then it probably COULD do 60Hz.
We'll have to wait and see. Still a couple weeks until the reviews start pouring out when the embargo is lifted.
iRun26.2
macrumors 68020
My bad. I should have had my reading glasses on!
iRun26.2
macrumors 68020
I suspect that if the rMB can only drive 4K at 30Hz, because of thermal constraints (60Hz requires active cooling), then the M Core processor will have little processing power (generating heat) available for anything else.
This, if you are using a 4K monitor with your rMB, your turbo mode power will probably be much shorter than usual before the thermal limit is reached.
This, if you are using a 4K monitor with your rMB, your turbo mode power will probably be much shorter than usual before the thermal limit is reached.
- We have our answer. Apple now officially lists support for 4K at 60Hz on the Retina MacBook, though there currently aren't any cables available to actually do it...
Apple said:
Salty Pirate
macrumors 6502a
skip ip if it is 30 Hz. It will look terrible.
travishill
macrumors regular
Unfortunately Apple updated their article to explicitly remove Retina Macbook from the 4k 60hz list. Perhaps they'll re-add it when their own DisplayPort Multiport adapter ships (if such a thing will eventually exist...) But for now it's a no-go.
ctyrider
macrumors 65816
DisplayPort adapter isn't the issue here. The GPU and lack of active cooling is the reason why rMB cannot support 4K@60Hz.
travishill
macrumors regular
Not necessarily. Active cooling can also be recommended when pushing beyond the default TDP- which Apple certainly does. So it could be that the new Macbooks could handle the necessary heat dissipation in their design. Or perhaps they already use that extra headroom and they can't spare any more.
Either way, I'll bet Skylake Macbook's have it sorted out...