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Macs4u

Suspended
Original poster
Apr 19, 2008
387
352
Stoke on Trent
Hi,

I have the i5 Mac mini 2018 and using a 4k monitor. Scaling is hampering the performance as I'm scaling at 2560x1440 (1080p on my monitor looks too big).

My question is this..

If I buy an external GPU, and buy another monitor which is 2560x1440, could I have dual monitor and use the main display as 1440p with no scaling and have the other as 4k no scaling ?

I plan to use davinci resolve mostly so would have the actual 4k footage shown on the 4k monitor and have the timeline and editing page etc on the 1440p monitor which is the best of both worlds then..

Matt
 

Stephen.R

Suspended
Nov 2, 2018
4,356
4,746
Thailand
How much memory do you have?

On my 2018 Mini, a single 4K display will scale to "looks like 2560x1440" pretty much fine, but two scaled displays is when you get some... turbulence.

But others have reported poor performance with low memory (which makes sense as the iGPU uses system memory), so that may be the issue in your case.

However to answer your original question yes you could run both unscaled from the eGPU - and you could run the 4K scaled (i.e. when you're not editing video) from the eGPU without issue too. Or you could run the 4K from the eGPU and the 2K from the mini (if you have FileVault enabled theres some hinky-ness that means you can't use displays attached to eGPUs before you login)
 

Macs4u

Suspended
Original poster
Apr 19, 2008
387
352
Stoke on Trent
Hi I have the i5 6 core, 256gb SSD and 8gb ram. Was going to upgrade the ram anyway but at the moment it's 8gb. Tbh I thought it would run faster than it does. Animations are quite choppy which I have been told is due to me scaling to look like 2560x1440 on a 4k monitor. If I get an external GPU and 16gb ram, I would be able to do 1x monitor at 1440p and 1x monitor at 4k (to show the output from davinci resolve) and it should run much better than it is now?

P.S Is yours the i5 6 core? How do you find it? I also tried running Logic Pro X on this and was getting very stuttery audio on anything below 512 samples which is terrible. Kept showing 1 core spiking to max all the time. My old 2012 MacBook Pro i7 had none of them issues. I know this is only a 6 core with no hyperthreading, but I would have thought an 8th gen intel would be more powerful than a 2012 intel?
 

Stephen.R

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Nov 2, 2018
4,356
4,746
Thailand
So to clarify no my machine is not the same spec as yours, mine is i7/64Gb/500Gb.

8GB RAM is not really enough to run a 4K display on the iGPU. You can absolutely run a single 4K in scaled mode with more memory (I've seen reports 16 is enough, I've only experienced it with the 64GB because that's how I ordered it).

If you ran the 4K at native (i.e. 1:1 pixels) and the 2(.5)K screen as well, you should get away with the iGPU (with more memory) - I'm able to run 2x4K scaled (at the 'default' scaling) without any major issues, and 1:1 should be less work. That doesnt mean an eGPU won't help, but you could try upgrading the memory first, as that will absolutely help the computer in general. It's possible the eGPU won't make a noticeable difference beyond what more memory allows the iGPU to do (in terms of the general UI responsiveness).

I would guess performance issues are also related to memory. 8GB memory is the new 16GB iPhone - sure, it might actually be the best option for some people but most people will hit a bottleneck.
 
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