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wadek

macrumors member
Original poster
Oct 11, 2007
41
11
I've googled several searches, but can't seem to find anything that directly answers this question. I'd plan on connecting a monitor via DisplayPort into the USB-C dock I have (https://eshop.macsales.com/item/OWC...0.1963794534.1521739501-1821787603.1519993181), although HDMI would also be possible. 2560x1080 seems likely, but would prefer 3440x1440 if possible. Lagging would not be a huge issue as it would me mostly for spreadsheets and multiple static windows open simultaneously. Thanks for any input.
 
The MacBook can support up to 3840x2160 at 60 Hz, but only if you have the right USB-C adapter (or a direct USB-C connection) and yes 3440x1440 at 60 Hz is also supported. Do a search here as it's been posted before.

Note though, one issue is making a setup which will not only connect the monitor but which will also keep the MacBook charged. This is one reason having just one USB-C port on the MacBook is irritating.
 
The MacBook 12" can do 3840 x 2160 at 60 Hz. 3440 x 1440 is lower, so it can do that as well at 60 Hz.

I don't remember whether the OWC USB-C dock supports 60 Hz at those resolutions.
 
The MacBook 12" can do 3840 x 2160 at 60 Hz. 3440 x 1440 is lower, so it can do that as well at 60 Hz.

I don't remember whether the OWC USB-C dock supports 60 Hz at those resolutions.

I've not found a single adapter / dock that will support that resolution @ 60hz. I ran into this myself when looking for a solution, as I was considering the MacBook (how to keep it plugged in while simultaneously driving a 34" Curved UltraWide).
 
I've not found a single adapter / dock that will support that resolution @ 60hz. I ran into this myself when looking for a solution, as I was considering the MacBook (how to keep it plugged in while simultaneously driving a 34" Curved UltraWide).
- A simple USB-C to DisplayPort cable or adaptor will. But many of the multiport ones max out at 30 Hz - probably to ensure USB 3.0.
 
- A simple USB-C to DisplayPort cable or adaptor will. But many of the multiport ones max out at 30 Hz - probably to ensure USB 3.0.

Oh definitely. I have a USB-C to HDMI that works perfectly fine @ 60hz. The problem is that the MacBook only has one USB-C port, so you can't charge while attached to a monitor without a dock / multi-port adapter.

edit: and it's *those* adapters that don't support 60hz.
 
- A simple USB-C to DisplayPort cable or adaptor will. But many of the multiport ones max out at 30 Hz - probably to ensure USB 3.0.
Yes, the 5 Gbps USB-C port of the MacBook does not provide enough bandwidth to support both 2160p60 and USB 3, so the default is to sell them with 2160p30 support and USB 3.

However, you can get ones that will support 2160p60 but with just USB 2. In fact, some of them are actually the same adapters, but with a different firmware.

The easiest solution is just to get a 4Kp60 USB-C monitor that supports charging, but it's quite pricey.

---

BTW, rumour has it that the 2019 Ice Lake model quad-core Y series will finally add USB-C 10 Gbps and Thunderbolt support, so if true, that would mean a 2019-2020 MacBook could get USB 3 and 2160p60 from one port simultaneously.
 
Thanks for the useful information. Just wanted to make sure it would at least display before laying out any $$$. I'm not too worried if the 3440x1440 is only 30Hz for my usage, and could lower the resolution if there were a need for a faster refresh rate.
 
Thanks for the useful information. Just wanted to make sure it would at least display before laying out any $$$. I'm not too worried if the 3440x1440 is only 30Hz for my usage, and could lower the resolution if there were a need for a faster refresh rate.
No! Don’t do that. Don’t drive it at a lower resolution. It won’t look so hot. The 3440 ultrawide already isn’t retina, but doesn’t look bad native.

I wish I still had pictures of mine to show you...
 
Yes, the 5 Gbps USB-C port of the MacBook does not provide enough bandwidth to support both 2160p60 and USB 3, so the default is to sell them with 2160p30 support and USB 3.
- 5 Gbps is for USB data. It has no bearing on display signals. The USB-C port can do full DisplayPort 1.2, which is north of 17 Gbps. But when it has to do that, it encroaches on the lanes normally needed for USB data, thus only leaving enough lanes for USB 2.0.
 
- 5 Gbps is for USB data. It has no bearing on display signals. The USB-C port can do full DisplayPort 1.2, which is north of 17 Gbps. But when it has to do that, it encroaches on the lanes normally needed for USB data, thus only leaving enough lanes for USB 2.0.
Yes, there is not enough bandwidth to support both 2160p60 and 5 Gbps USB 3 simultaneously.

The next iteration of the port in 2019 should (hopefully) support both simultaneously, and it should also support TB3.
 
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Apple multiport AV adapter with the HDMI cable I also purchased from Apple provide 3440x1440 @60Hz
Mine is 2016 model, though even 2015 models support that.
 
Apple multiport AV adapter with the HDMI cable I also purchased from Apple provide 3440x1440 @60Hz
Mine is 2016 model, though even 2015 models support that.

Apple specs on the product page for the adapter:

Up to 1080p @ 60hz
3840x2160 @ 30hz

So yes, it will support 3440x1440, but Apple states only @ 30hz.
 
Apple multiport AV adapter with the HDMI cable I also purchased from Apple provide 3440x1440 @60Hz
Mine is 2016 model, though even 2015 models support that.
If true, that's great!


Apple specs on the product page for the adapter:

Up to 1080p @ 60hz
3840x2160 @ 30hz

So yes, it will support 3440x1440, but Apple states only @ 30hz.
Apple makes no mention of 3440x1440.

The frequency specs for 3840x2160 (8.29 Megapixels) don't have to necessarily apply for 3440x1440 (4.95 Megapixels).
 
Apple makes no mention of 3440x1440.

The frequency specs for 3840x2160 (8.29 Megapixels) don't have to necessarily apply for 3440x1440 (4.95 Megapixels).

Notice the words “up to”. That means up to 1080p and anything below it will be 60hz, and anything above will be @ 30hz.
 
IIRC, 2560x1440p60 works fine through that adapter.

I wasn't sure about 3440x1440p60, but Precursor says it works.

No idea on that. I’m only going off of what Apple says on their site, and my experience from using it. My ultrawide didn’t run @ 60hz until I used a usb-c to hdmi cable.
 
No idea on that. I’m only going off of what Apple says on their site, and my experience from using it. My ultrawide didn’t run @ 60hz until I used a usb-c to hdmi cable.
I thought I read somewhere that Apple updated the support for that adapter sometime in 2016. I could be mistaken though. When did you test?
 
IIRC, 2560x1440p60 works fine through that adapter.

I wasn't sure about 3440x1440p60, but Precursor says it works.
There was a couple threads in this forum 1.5-2 years ago where some forum members even posted their screenshots working 60Hz on 3440x1440.
You are correct about the pixel count, it's all about the bandwidth really. 4.95M pixels is way less than 8.29M pixels.
 
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